Nissan 3.0L, 3.3L, 3.5L Index of Articles http://troubleshootmyvehicle.com/Table/Nissan-Index-of-Articles/Nissan-3.0L-3.3L-3.5L-Index-of-Articles/ Thu, 23 Oct 2014 19:52:00 +0000 Joomla! - Open Source Content Management en-us troubleshootmyvehicle@hotmail.com (troubleshootmyvehicle.com) How to Test the MAP Sensor P0105[br] (3.3L Nissan Pathfinder) http://troubleshootmyvehicle.com/nissan/3.0L-3.3L-3.5L/how-to-test-the-map-sensor-1 http://troubleshootmyvehicle.com/nissan/3.0L-3.3L-3.5L/how-to-test-the-map-sensor-1 How to Test the MAP Sensor (3.3L Nissan Pathfinder)

Testing the MAP sensor (and the resulting P0105 code) on your Nissan Pathfinder isn't hard and in this tutorial I'll show you how to.

You don't need any expensive testing equipment. You don't even need a scan tool. All you need is a multimeter.

Here are the main points of this tutorial at a quick glance:

  1. MAP Sensor Circuit Descriptions.
  2. Before You Start the MAP Sensor Test.
  3. TEST 1: Checking for the MAP Sensor Signal.
  4. TEST 2: Checking that MAP Sensor is Getting Power.
  5. TEST 3: Verifying the MAP Sensor is Getting Ground.

MAP Sensor Circuit Descriptions

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As you're already aware, the MAP sensor on your Nissan Pathfinder has 3 wires coming out of its harness connector.

These wires (circuits) are tasked with feeding power and ground and taking the MAP signal back to the PCM.

All of the tests in this tutorial are done to the harness connector. In the image viewer you'll see the pin outs for the MAP sensor itself and its harness connector.

Nissan Pathfinder MAP Sensor Pin Out
Pin Description
1 Sensor Ground
2 MAP Sensor Signal
3 5 Volt Reference

Before You Start the MAP Sensor Test

Before you start the MAP sensor test on your Nissan Pathfinder (Frontier or QX4), you need to make sure that the sensor is getting vacuum (after the engine has started).

If the MAP sensor is not getting vacuum... then the most likely culprit is the MAP/BARO switch solenoid valve that is defective (since this solenoid valve is the one that provides the MAP sensor with vacuum) or misrouted vacuum hoses.

For more information take a look at the following tutorial:

  1. MAP/BARO Pressure Solenoid Test (1996-2004 3.3L Pathfinder).

TEST 1: Checking for the MAP Sensor Signal

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In this first test we're going to tap into the middle wire of the MAP sensor with a multimeter and see if the map sensor is producing a map signal when we manually apply vacuum to it.

You can apply vacuum to the MAP sensor with a vacuum pump or you can use the good ole' lungs (although using a vacuum pump is the most accurate way of testing the map sensor).

NOTE: Although you'll be bench testing the MAP sensor of your Nissan Pathfinder... you still need to leave the MAP sensor connected to its harness connector so that it can get both power and ground (to produce a signal).

OK, these are the test steps:

  1. 1

    Remove the MAP sensor from its location near the air filter box (if you need to gain access to its vacuum port).

    Once you have removed it, reconnect it back to its harness connector.

  2. 2

    Select Volts DC on your multimeter and probe the middle wire of the MAP sensor with the red multimeter lead.

    1. This is the wire that connects to the MAP sensor engine harness connector's terminal labeled with the number 2 in the image viewer.
    2. The best way to get to the signal inside the wire is using a wire piercing probe (to see what this tool looks like, click here: Wire-Piercing Probe).
  3. 3

    Ground the black multimeter lead on the battery's negative terminal.

  4. 4

    Now, connect your vacuum pump to the MAP sensor and turn the Key to the ON position (don't start the engine).

  5. 5

    With the key On and no vacuum applied to the MAP sensor your multimeter should display:

    1. 3.2 to 4.8V (this is no vacuum applied to the MAP sensor).

    Apply Vacuum. As you apply vacuum, your multimeter's voltage reading should start to decrease. Once you have reached 7.8 in. Hg vacuum, your multimeter should read:

    1. 1.0 - 1.4 Volts DC.
    2. See photo 3 of 3 in the image viewer above to see these numbers on the vacuum pump.

NOTE: What you're looking for, as you apply and release vacuum is for the multimeter to show a decrease in voltage (as you apply vacuum) and an increase in the voltage back to 4.5+ volts (as you release vacuum).

Let's take a look at what your test results mean:

CASE 1: The MAP sensor's voltage decreased as you applied vacuum- This tells you that the MAP sensor is OK and not the true cause of the MAP sensor codes.

This also confirms that your Nissan Pathfinder's (Frontier, QX4) MAP sensor is getting power (5 Volts) on wire and ground.

CASE 2: The MAP sensor's voltage DID NOT decrease as you applied vacuum- This usually means that the MAP sensor is BAD... but we'll need to make sure that the MAP sensor is getting both power and ground.

For this test, go to TEST 2: Checking that MAP Sensor is Getting Power.


TEST 2: Checking that MAP Sensor is Getting Power

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If in TEST 1 your Nissan Pathfinder's MAP sensor did not create a signal... then there's a good chance that the sensor is missing either power or ground.

So the next step is to verify that the MAP sensor is getting 5 volts on terminal number 3 of its harness connector (see illustration in the image viewer).

NOTE: You can check for these 5 volts with the MAP sensor connected or disconnected from its harness connector.

This is what you'll need to do:

  1. 1

    Place your multimeter in Volts DC mode and with the red multimeter lead, probe the wire labeled with the number 3.

    1. Avoid probing the front of the connector... to avoid damaging the female metal terminal.
    2. The best way to get to the Signal inside the wire is using a Wire Piercing Probe (to see what this tool looks like, click here: Wire-Piercing Probe).
  2. 2

    Ground the black multimeter lead directly on the battery's negative terminal.

  3. 3

    Turn the key to the ON position (but don't start the engine). If all is OK, your multimeter should read 4.5 to 5 Volts DC.

Let's take a look at your test results:

CASE 1: 4.5 to 5 Volts are present- So far so good, since this means that the PCM is supplying power to the manifold absolute pressure (MAP) sensor.

The next step is to make sure that the PCM is feeding your Nissan's MAP sensor with ground. For this test, go to TEST 3: Verifying the MAP Sensor is Getting Ground.

CASE 2: 4.5 to 5 Volts ARE NOT present- Recheck your multimeter connections and retest...

... If after checking all of your multimeter connections and making sure the Key is in the ON position AND your multimeter does not register the 4.5 to 5 Volts DC, then you've found the reason for the MAP sensor code/failure.

Without power in this circuit, the MAP sensor will not work. Now, it's beyond the scope of this article to test for this missing Voltage, but the most likely cause will be an ‘open’ short between the PCM connector and the MAP sensor connector.

TEST 3: Verifying the MAP Sensor is Getting Ground

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So far you've verified two important things about your Nissan's MAP sensor:

One: The MAP sensor is NOT producing a signal (TEST 1).

Two: That it's getting power on terminal number 3 of the harness connector (TEST 2).

The next step is to check that terminal number 1 of the sensor's harness connector is feeding the MAP sensor ground.

IMPORTANT: The PCM is the one that provides this ground internally, so be careful and don't intentionally or accidentally short this wire to battery voltage or you'll fry the PCM.

This is what you'll need to do:

  1. 1

    Place your multimeter in Volts DC mode and with the black multimeter lead, probe the wire that connects to the terminal labeled with the number 1 of the MAP sensor's harness connector.

    1. Avoid probing the front of the connector... to avoid damaging the female metal terminal.
    2. The best way to get to the signal inside the wire is using a Wire Piercing Probe (to see what this tool looks like, click here: Wire-Piercing Probe).
  2. 2

    Connect the red multimeter lead directly to the battery's positive (+) terminal.

  3. 3

    Turn the Key to the ON position (but don't start the engine).

    If all is OK, your multimeter should read 10 to 12 Volts DC.

Let's take a look at your test results:

CASE 1: Your multimeter showed battery voltage- So far so good, since this means that the PCM is supplying power to the manifold absolute pressure (MAP) sensor.

This confirms that the manifold absolute pressure (MAP) sensor is BAD and needs to be replaced. Why? Well, because so far you have confirmed that:

  1. The MAP sensor is not producing a signal when vacuum is applied to it (TEST 1).
  2. The MAP sensor is getting its 5 Volts (TEST 2).
  3. In this test step, you've confirmed that the MAP sensor is getting ground.

Taking all of these 3 test results... you can conclude with confidence that you need to replace the MAP sensor with a new one.

CASE 2: Your multimeter did NOT show battery voltage- Recheck your multimeter connections and retest...

... If after checking all of your multimeter connections and making sure the Key is in the ON position AND your multimeter does not register the 10 to 12 Volts DC, then you've found the reason for the MAP sensor code/failure.

Without ground in this circuit, the MAP sensor will not work. Now, it's beyond the scope of this article to test for this missing ground, but the most likely cause will be an ‘open’ between the PCM connector and the MAP sensor connector.


Where to Buy the MAP Sensor and Save

The MAP sensor on your Nissan Pathfinder (Frontier, QX4) isn't cheap. So if the MAP tests confirm that it's bad and you need to replace it... take a look at the bottom links and do some comparison shopping:

More 3.3LNissan Test Tutorials

You can find a complete list of tutorials here: Index of Nissan 3.0L, 3.3L, 3.5L Articles.

Here's a sample of the tutorials you'll find in the index:

  1. MAP/BARO Pressure Solenoid Test (1996-2004 3.3L Pathfinder).
  2. P0130, P0150 Front O2 Sensor Tests (1996-2000 3.3L Nissan Pathfinder).
  3. Throttle Position Sensor Test (Nissan 3.3L Pathfinder, Xterra, Frontier).
  4. How to Troubleshoot a No Start (Nissan 3.0L, 3.3L, 3.5L).
  5. How to Test Engine Compression (Nissan 3.0L, 3.3L, 3.5L).
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troubleshootmyvehicle@hotmail.com (Abraham Torres-Arredondo) Nissan 3.0L, 3.3L, 3.5L Index of Articles Tue, 20 Aug 2013 14:11:50 +0000
MAP/BARO Pressure Solenoid Test[br] (1996-2004 3.3L Pathfinder) http://troubleshootmyvehicle.com/nissan/3.0L-3.3L-3.5L/MAP-BARO-solenoid-tests-1 http://troubleshootmyvehicle.com/nissan/3.0L-3.3L-3.5L/MAP-BARO-solenoid-tests-1 How to Test MAP/BARO Switch Solenoid Valve (3.3L, 3.5L Nissan Pathfinder- 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004)

Testing the MAP/BARO switch solenoid valve (and the resulting P1105 trouble code) on your Nissan Pathfinder isn't hard and it's something you can do yourself.

In this tutorial, I'll show you what you need to do to find out if it's bad (or not) in a step-by-step way.

NOTE: Although this tutorial is written with the Nissan 3.3L equipped Pathfinder in mind... it also applies to the 3.5L equipped Pathfinder (QX4) and 3.3L/3.5L Frontier, since the same type of BARO/MAP switch solenoid valve is used on both vehicles. For more specifics, see the ‘Applies To:’ box on the right.

Here's the content of this tutorial at a quick glance:

  1. MAP/BARO Switch Solenoid Valve Diagnostic Essentials.
  2. TEST: Bench Testing the MAP/BARO Switch Solenoid Valve.
  3. More Nissan Pathfinder (Frontier, Xterra) Tutorials.
  4. Nissan Pathfinder Auto Parts Deals.

MAP/BARO Switch Solenoid Valve Diagnostic Essentials

Vacuum Diagram of the MAP/BARO Switch Solenoid Valve (Nissan Pathfinder)

What it does: The MAP/BARO switch solenoid valve is tasked with the job of providing manifold vacuum to the MAP sensor a few seconds after the engine starts up. Why?...

... So that the MAP sensor can take a barometric pressure reading before the MAP/BARO switch feeds it intake manifold vacuum.

So, when it doesn't switch from barometric pressure to manifold vacuum pressure (after your Nissan Pathfinder starts up), your Nissan Pathfinder's (or Frontier's) PCM lights up the check engine light and sets a P1105 trouble code and MAP sensor code.

Vacuum hose routing: Using the illustration above, here are the MAP/BARO switch solenoid valve vacuum hose specifics:

  1. Vacuum hose port A
    1. To air cleaner box.
  2. Vacuum hose port B
    1. To MAP sensor (called the absolute pressure sensor by Nissan).
  3. Vacuum hose port C
    1. Manifold vacuum.

Common Problems: The most common causes of a P1105 MAP/BARO switch solenoid valve trouble code are:

  1. Misrouted vacuum hoses.
  2. Broken vacuum hoses.
  3. Failed MAP/BARO switch solenoid valve.

What you need to do first: Before you start testing the MAP/BARO switch solenoid valve itself... you need to make sure that:

  1. All vacuum hoses that connect to the solenoid valve are routed correctly.
  2. The vacuum hoses that connect to the solenoid valve are not broken or leaking vacuum.
  3. The vacuum hose that connects to the vacuum port labeled with the letter C (in the illustration above) has vacuum with the engine running.
  4. MAP sensor is getting vacuum a few seconds after the engine starts.
    1. If the MAP sensor is NOT getting vacuum, then proceed to TEST 1.

TEST: Bench Testing the
MAP/BARO Switch Solenoid Valve

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Now that you've checked that all of the vacuum hoses (that connect to the MAP/BARO switch solenoid valve) are routed correctly, that the switch is being fed vacuum and the MAP sensor is not getting vacuum (after the engine has started)...

... The next step is to bench test the solenoid valve itself to see if it's fried (or not).

Bench testing the MAP/BARO switch solenoid valve simply involves removing it and applying power and ground to it (with jumper wires). And in this test step I'll show you how.

Here's what you need to do:

  1. 1

    Remove the MAP/BARO switch solenoid valve, from its location underneath the MAP sensor (see photo 3 of 3 in the image viewer above).

  2. 2

    Apply battery voltage to pin 1 and ground to pin 2 of the solenoid valve using jumper cables.

    NOTE: Use a fused jumper wire to apply 12 volts from your Nissan Pathfinder's battery to pin 1.

Vacuum Diagram of the MAP/BARO Switch Solenoid Valve (Nissan Pathfinder)
  1. 3

    With battery power and ground applied:

    1. Air should now pass between ports A and B.
    2. Air should NOT pass between ports B and C.
  2. 4

    With battery power and ground removed:

    1. Air should NOT pass between ports A and B.
    2. Air should pass between ports B and C.

Let's take a look at your test results:

CASE 1: Air passed (and not passed) as specified. This test result tells you that the MAP/BARO switch solenoid valve is OK and not the cause of the P1105 diagnostic trouble code.

If the P1105 trouble code is still present... then your next step is to check that the two circuits that feed power and the activation signal from the PCM are not shorted to ground or ‘open’. Although this is beyond the scope of this tutorial, you have eliminated the MAP/BARO switch solenoid valve as being defective.

CASE 2: The solenoid valve did not work as specified. This test result tells you that the MAP/BARO solenoid is fried and needs to be replaced with a new one.


More Nissan Pathfinder (Frontier, Xterra) Tutorials

You can find a complete list of tutorials here: Nissan 3.0L, 3.3L, 3.5L Index of Articles.

Here's a sample of the type of tutorials you'll find in the index:

  1. P0130, P0150 Front O2 Sensor Tests (1996-2000 3.3L Nissan Pathfinder).
  2. How to Test the Idle Switch (Nissan 3.3L Pathfinder, Xterra, Frontier).
  3. Throttle Position Sensor Test (Nissan 3.3L Pathfinder, Xterra, Frontier).
  4. How to Troubleshoot a No Start (Nissan 3.0L, 3.3L, 3.5L).
  5. How to Test Engine Compression (Nissan 3.0L, 3.3L, 3.5L).

Nissan Pathfinder Auto Parts Deals

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troubleshootmyvehicle@hotmail.com (Abraham Torres-Arredondo) Nissan 3.0L, 3.3L, 3.5L Index of Articles Fri, 16 Aug 2013 14:01:33 +0000
P0130, P0150 Front O2 Sensor Tests[br] (1996-2000 3.3L Nissan Pathfinder) http://troubleshootmyvehicle.com/nissan/3.0L-3.3L-3.5L/P0130-and-P0150-diagnostic-tests-1 http://troubleshootmyvehicle.com/nissan/3.0L-3.3L-3.5L/P0130-and-P0150-diagnostic-tests-1 How to Test Upstream Oxygen Sensors (1997-2000 3.3L Nissan Pathfinder)

In this tutorial I am going to show you how to test diagnostic trouble codes P0130 and P0150 on your 3.3 liter equipped Nissan Pathfinder.

These codes indicate a problem with the front O2 sensors which are the sensors located before the catalytic converter for Bank 1 and Bank 2.

This tutorial applies to the 1997 to 2000 3.3 liter V6 Nissan Pathfinder.

Here are the main points of this tutorial at a quick glance:

  1. P0130 and P0150 Diagnostic Essentials.
  2. Diagnosing Trouble Codes P0130 and P0150.
  3. TEST 1: Checking Upstream Oxygen Sensor Performance.
  4. TEST 2: Manually Inducing a Rich Condition.
  5. TEST 3: Checking the Resistance of the O2 Heater Element.
  6. TEST 4: Checking the Continuity Between the O2 Sensor and PCM.
  7. Where to Buy your Nissan Pathfinder’s O2 Sensors and Save.
  8. More Test Articles.

P0130 and P0150 Diagnostic Essentials

Identifying Bank 1 and Bank 2 3.3L Nissan Pathfinder

Usually what causes these two codes to pop up on your Nissan Pathfinder is a failed right (or left) upstream oxygen sensor but not always.

Thankfully, by doing some specific tests, you and I can check to see if they're bad (or not) before replacing them.

Before we jump into the tests, here's some specific information about these two codes that will help us understand exactly what they're trying to tell us:

P0130: O2 Sensor Circuit Malfunction (Bank 1 Sensor 1). This trouble code lets us know that the PCM is detecting that:

  1. The front O2 sensor for Bank 1 is not switching between .2 to .8 volts (as the engine is running).
  2. That the front O2 sensor for Bank 1 is stuck producing an output voltage of .2 - .4 volts DC.
  3. That the fault could lie in the front oxygen sensor itself or in the wiring between the sensor and the fuel injection computer.
  4. NOTE: Bank 1 is the bank that houses cylinders 1, 3, and 5.
  5. Bank 1 Sensor 1 is commonly referred to as:
    1. Right front oxygen sensor.
    2. Upstream right oxygen sensor.
    3. Bank 1 Sensor 1.
    4. O2S11.

P0150: O2 Sensor Circuit Malfunction (Bank 2 Sensor 1):

  1. The front O2 sensor for Bank 2 is not switching between .2 to .8 volts (as the engine is running).
  2. That the front O2 sensor for bank 2 is stuck producing an output voltage of .2 - .4 volts DC.
  3. That the fault could lie in the front oxygen sensor itself or in the wiring between the sensor and the fuel injection computer.
  4. NOTE: Bank 2 is the bank that houses cylinders 2, 4, and 6.
  5. Bank 2 Sensor 1 is commonly referred to as:
    1. Left front oxygen sensor.
    2. Upstream left oxygen sensor.
    3. Bank 2 Sensor 1.
    4. O2S21.

As you can see from the information above... both codes (P0130 and P0150) aren't accusing either of the two upstream oxygen sensors as having failed... since quite a few things can cause them to stay stuck producing a fixed voltage between .2 - .4 volts.

Diagnosing Trouble Codes P0130 and P0150

Getting to the bottom of what's causing these 2 codes to light up the check engine light (CEL) on your Nissan Pathfinder involves 4 specific tests.

NOTE: Both the right and left upstream oxygen sensors are tested in the exact same way... so all of the tests (in this tutorial) apply to them both.

  1. The first test is to confirm that the oxygen sensor's output isn't the right output.
    1. Go to TEST 1: Checking Upstream Oxygen Sensor Performance.
  2. The second test involves creating a rich air fuel mixture and seeing if the right and left upstream O2 sensors react to it.
    1. Go to TEST 2: Manually Inducing a Rich Condition.
  3. The third test involves measuring the resistance of the internal heater of the upstream oxygen sensor.
    1. Go to TEST 3: Checking the Resistance of the O2 Heater Element.
  4. The last test involves testing the continuity of the oxygen sensor's wires between its harness connector and the fuel injection computer's harness connector.
    1. Go to TEST 4: Checking the Continuity Between the O2 Sensor and PCM.

TEST 1: Checking Upstream Oxygen Sensor Performance

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The very first thing that we need to do is check the right (or left) O2 sensor output voltage to see if it's stuck between .2 to .4 volts DC after the engine has started and warmed up.

This can be very easily accomplished using a scan tool with live data mode.

If you don't have a scan tool don't panic because you can use a multimeter to test for the right (or left) upstream oxygen sensor's output voltage (and I'll also include how to do it).

Is you don't have a scan tool and are thinking about buying one or need to upgrade your code reader, check out my recommendation here: Actron CP9580 Scan Tool Review.

These are the test steps:

  1. 1

    Connect your scan tool, turn the key to the On position, and go to its live data mode.

    If you're using a multimeter: Place the multimeter in volts DC mode, connect the red lead to the wire to the middle wire of the upstream oxygen sensor you're testing, and ground the black test lead on the battery's negative terminal.

  2. 2

    Start your Pathfinder's engine and let it warm up.

    In the meantime, scroll down to the PID's labeled: O2S11 and O2S21 (see the image in the image viewer).

    PID O2S11 represents the output from the right upstream oxygen sensor and PID O2S21 represents the left upstream oxygen sensor.

  3. 3

    Once the engine has reached normal operating temperature, PID O2S11 and O2S21 should show a constant sweeping voltage signal of .2 to .8 volts.

    In other words: The voltage should move constantly between .2 volts to .8 volts the entire time the engine is running.

    If you're using a multimeter: Your multimeter should register a voltage (for the upstream O2 sensor you're testing) that's constantly moving between .2 volts to .8 volts as the engine runs.

CASE 1: The upstream oxygen sensor output voltage constantly moved between .2 to .8 volts. This test results tells you that the oxygen sensor that you're observing either on your scan tool or with your multimeter is functioning correctly at this point in time.

This test results also tells you that the problem is intermittent since it's not present at this time.

CASE 2: The upstream oxygen sensor output voltage stayed stuck between .2 to .4 volts. This test result definitely tells you that the upstream O2 sensor you're observing on your scan tool or multimeter has a problem.

The next step is to manually induce a rich condition and see if the O2 sensor that you're observing responds to this rich condition. If it doesn't respond to it... then we know that it has failed and needs to be replaced. For this test go to: TEST 2: Manually Inducing a Rich Condition.


TEST 2: Manually Inducing a Rich Condition

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You've reached this point because in TEST 1 you confirmed that the right (or left) upstream oxygen sensor is stuck producing a continuous voltage (when it should be alternating between .2 and .8 volts).

The next step is to manually induce a rich condition by spraying carburetor spray into a vacuum hose while the engine runs.

If the right (or left) upstream oxygen sensor on your Nissan Pathfinder is working correctly... as soon as the carb. spray gets burned in the cylinder... its output voltage should hit .8 to 1.0 volt DC.

IMPORTANT: Take all necessary safety precautions since this test requires that you work around a running engine. Stay alert, use common sense, and be careful.

Here are the step-by-step instructions:

  1. 1

    Start your Pathfinder's engine, scroll down to the left and right upstream oxygen sensor PIDs labeled O2S11 and O2S21.

  2. 2

    Make sure your Pathfinder's engine has reached normal operating temperature before you proceed to the next step.

  3. 3

    Have a helper spray a little bit of carburetor cleaner into the intake manifold via a small vacuum hose with the engine running and while you observe the scan tool's upstream oxygen sensor PIDs.

  4. 4

    As soon as the carburetor spray hits the inside of the intake manifold (via the vacuum hose) and enrichens the air/fuel mixture, your scan tool should read 0.800 to 1.0 volt for both O2S11 and O2S21.

    You can repeat step 3 several times, if you need to make sure of your test result.

Let's take a look at what your test results mean:

CASE 1: The O2S11 and O2S21 values increased to .8 to 1 V and stay there as long as you were spraying carb spray. This test result confirms that both the left and right oxygen sensors are OK.

CASE 2: The O2S11 and O2S21 values values did not shoot up as the carb spray was being sprayed. This result confirms that there's a problem with the O2 sensor you're observing on the scan tool or with the multimeter.

Generally, this means that the O2 sensor you're observing/testing is bad... I suggest doing the other two tests (in this tutorial) to make sure. For the first (of two), go to TEST 3: Checking the Resistance of the O2 Heater Element.

TEST 3: Checking the
Resistance of the O2 Heater Element

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In this test we're going to check the resistance of the heater element within the right (or left) upstream oxygen sensor.

You don't have to remove the right (or left) upstream O2 sensor from your Nissan Pathfinder to test the resistance of a heater element... since its connector is easily accessible from the engine compartment.

Since the Nissan factory resistance specifications (for the heater element) calls for the right (or left) upstream sensor to be at room temperature (77 °F (25 °C)), you're going to have to perform this test with a completely cold engine.

NOTE: The illustration in the image viewer applies to both the left and right upstream oxygen sensors on your Nissan Pathfinder.

These are the test steps:

  1. 1

    With the key in the Off position, disconnect the oxygen sensor that you're gonna' test.

    NOTE: The engine (and thus the O2 sensor) has to be completely at room temperature.

  2. 2

    Measure the resistance between terminals 1 and 3 of the upstream oxygen sensor you're testing (use the illustration in the image viewer above to identify the correct O2 sensor terminals).

    The resistance between these two outer terminals of the upstream oxygen sensor should be between 2.3 to 4.3 Ohms (Ω) at 77 °F (25 °C) if all is OK (with the heater element).

  3. 3

    Check for continuity between terminals 1 and 2 and check for continuity between terminals 2 and 3. If the upstream sensor is OK, there should NOT be any continuity between these terminals.

Let's take a look at what your test results mean:

CASE 1: The upstream O2 sensor heater element's resistance is within specification and there's no continuity between terminal 1 and 2 and between terminal 2 and 3. This is the correct and expected test result and tells you that the internal heater element of the upstream oxygen sensor you're testing is OK.

So far you have:

  1. Confirmed that the right (or left) upstream O2 sensor is stuck producing a continuous voltage in TEST 1.
  2. Confirmed that the right (or left) upstream O2 sensor does NOT react to a manually induced rich condition TEST 2.
  3. Confirmed that the heater element of the right (or left) upstream O2 sensor is within specification (in this test).

... Your next step is to go to: TEST 4: Checking the Continuity Between the O2 Sensor and PCM.

CASE 2: The upstream O2 sensor heater element's resistance is NOT within specification and/or there's continuity between the other terminals. This test result indicates a problem with the heater element of the upstream oxygen sensor you're testing. Replace the oxygen sensor.


TEST 4: Checking the
Continuity Between the O2 Sensor and PCM

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The last battery of tests is to make sure that the wire that connects to terminal number 2 of the right (or left) upstream oxygen sensor isn't shorted to ground or is ‘open’ somewhere between the sensor's harness connector and the PCM's connector.

This can easily be accomplished by doing a continuity test between the right (or left) upstream O2 sensor engine harness connector and the PCM harness connector and a continuity test between terminal number 2 and ground.

NOTE: The left upstream oxygen sensor terminal number 2 wire connects to pin number 51 of the PCM connector. The right upstream oxygen sensor terminal number 2 wire connects to pin number 50 of the PCM connector.

These are the step tests:

  1. 1

    Disconnect the battery's negative terminal and:

    1. Disconnect the upstream oxygen sensor (that you need to test) from its engine harness connector.
    2. Disconnect the PCM from its harness connector.
  2. 2

    Testing the right upstream O2 sensor, test continuity between:

    1. Terminal number 2 of the O2's engine harness connector and terminal 50 of the PCM's harness connector.
    2. Continuity should exist.
  3. 3

    Testing the left upstream O2 sensor, test continuity between:

    1. Terminal number 2 of the O2's engine harness connector and terminal 51 of the PCM's harness connector.
    2. Continuity should exist.
  4. 4

    Test the continuity between:

    1. Terminal number 2 and engine ground (see illustration 2 of 2).
    2. This test applies to both the right or left upstream oxygen sensor.
    3. Continuity should NOT exist.

CASE 1: All of the continuity tests showed no problems. This test result tells you that that are no ‘opens’ or shorts to ground in the circuit between the PCM's harness and the O2 sensor' harness connector.

Since you've reached this point because you have:

  1. Confirmed that the right (or left) upstream O2 sensor is stuck producing a continuous voltage in TEST 1.
  2. Confirmed that the right (or left) upstream O2 sensor does NOT react to a manually induced rich condition TEST 2.
  3. Confirmed that the heater element of the right (or left) upstream O2 sensor is within specification in TEST 3.

... You can correctly assume that the upstream O2 sensor you're testing is fried and needs to be replaced with a new one.

CASE 2: One or several of the continuity tests showed a problem. Check all of your connections and repeat a test one more time.

If the continuity tests confirm the problem... then repair the short to ground or the ‘open’ in the circuit. Repairing this issue will solve the right or left upstream O2 sensor diagnostic trouble code (P0130 or P0150) lighting up the check engine light on your Nissan Pathfinder.

Where to Buy your Nissan
Pathfinder's O2 Sensors and Save

If you walk into your local auto parts store you'll notice that the upstream O2 sensors for Bank 1 (right) and Bank 2 (left) are expensive. If you do need to buy new O2 sensors, check out the links below and save:

Right Upstream
Direct Fit
Right Upstream
Direct Fit
Left Upstream
Direct Fit
Left Upstream
Direct Fit

More Nissan Pathfinder Test Tutorials

You can find a complete list of tutorials here: Nissan 3.0L, 3.3L, 3.5L Index of Articles.

Below is a small sample of the tutorials you'll find in the index:

  1. How to Test the Idle Switch (Nissan 3.3L Pathfinder, Xterra, Frontier).
  2. Throttle Position Sensor Test (Nissan 3.3L Pathfinder, Xterra, Frontier).
  3. How to Troubleshoot a No Start (Nissan 3.0L, 3.3L, 3.5L).
  4. How to Test the Starter Motor (Nissan 3.0L, 3.3L).
  5. How to Test Engine Compression (Nissan 3.0L, 3.3L, 3.5L).
{loadposition contact_form}]]>
troubleshootmyvehicle@hotmail.com (Abraham Torres-Arredondo) Nissan 3.0L, 3.3L, 3.5L Index of Articles Fri, 16 Aug 2013 13:58:34 +0000
How to Test the Idle Switch [br](Nissan 3.3L Pathfinder, Xterra, Frontier) http://troubleshootmyvehicle.com/nissan/3.0L-3.3L-3.5L/how-to-test-the-idle-switch-1 http://troubleshootmyvehicle.com/nissan/3.0L-3.3L-3.5L/how-to-test-the-idle-switch-1 How to Test the Idle Switch (Nissan 3.3L)

The idle switch on your 3.3L Nissan Pathfinder (Frontier, Xterra, QX4) is part of the throttle position sensor assembly and can be easily tested with a simple multimeter resistance test.

In this tutorial, I'm gonna' show you how to test it and how to adjust it (if you need to replace it).

Here are the contents of this tutorial at a glance:

  1. Idle Switch Continuity Tests.
  2. Adjusting the Throttle Position Sensor Assembly.
  3. Where to Buy Your TP Sensor and Save.
  4. More Nissan 3.3L Test Tutorials.

If you need to test the throttle position sensor part of the idle switch, this tutorial will help: Throttle Position Sensor Test (Nissan 3.3L Pathfinder, Xterra, Frontier).

Idle Switch Continuity Tests

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Testing the idle switch involves measuring continuity between specific pins of the throttle position sensor assembly.

Since the TP sensor assembly is 2 sensors in 1 and has two connectors.... the pins that we're going to be testing are the ones that the gray connector connects to and these are labeled with the numbers 4, 5 and 6 in the illustration in the image viewer.

The bottom brown connector connects to the TP sensor part and supplies it with power, ground, and relays the throttle angle voltage signal to the PCM.

Idle Switch Closed Throttle Specifications
Throttle Angle Pins Ohms
Closed Throttle 5 and 6 No Continuity
Open Throttle 5 and 6 No Continuity
Idle Switch Open Throttle Specifications
Throttle Angle Pins Ohms
Closed Throttle 4 and 5 Continuity
Open Throttle 4 and 5 No Continuity

If the throttle switch on your Nissan Pathfinder (Xterra, Frontier, QX4) doesn't pass any of the above pin continuity tests... then, before replacing it, you need to make sure that it's not misadjusted. The next subheading will help you with this procedure.

Adjusting the Throttle Position Sensor Assembly

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If you need to remove and replace the throttle position sensor assembly... you'll need to adjust it to the correct specification before you bolt it down.

This is a pretty easy adjustment and in this section I'll show you how to do it.

NOTE: The TP sensor assembly needs to be connected to its connectors for this adjustment to take place.

This is what you'll need to do:

  1. Turn the ignition switch to its Off position and make sure the TP sensor assembly is connected to its connectors.
  2. Turn the ignition switch to its On position but don't start the engine.
  3. Place your multimeter in Volts DC mode and:
    1. Connect the red multimeter lead to the wire that connects to the pin labeled with the number 2 (see the illustration in the image viewer above).
    2. Ground the black multimeter lead on the battery negative terminal.
    3. NOTE: Remember the throttle position sensor assembly must remain connected to its connectors through the entire adjustment.
  4. Adjust the TPS sensor by rotating it until the output voltage is within specification:
    1. Specification: .3 to .7 volts DC.
  5. Once the output voltage has reached the above voltage specification, tighten the TP sensor assembly mounting bolts.
  6. Once you're done, recheck the output voltage to make sure the TP sensor didn't move on you when you tightened the two bolts.

Where to Buy Your TP Sensor and Save

Just recently one of my cousins needed to buy a TP sensor for her 1998 Nissan Pathfinder and I was shocked and how much paid for it at our local auto parts store! After all, the TP sensor she bought is a no-name brand Chinese knockoff that she paid over $100 (US) for.

I didn't have the heart to tell her that she could've bought it a whole lot cheaper online, but I will tell you and I'll show you where to buy it. You can buy it here:

Not sure the TP sensor listed fits your particular Nissan? Don't worry, they'll make sure it fits your Nissan, once you get to the TP sensor site, or they'll find the right one for you.

More Nissan 3.3L Test Tutorials

If this tutorial was helpful/informative, you can find a complete list of tutorials here: Nissan 3.0L, 3.3L, 3.5L Index of Articles.

Here's a sample of the tutorials you'll find there:

  1. How to Troubleshoot a No Start (Nissan 3.0L, 3.3L, 3.5L).
  2. How to Test Engine Compression (Nissan 3.0L, 3.3L, 3.5L).
  3. Mass Air Flow (MAF) Sensor Test 3.3L Frontier, Quest, Pathfinder, XTerra (at: easyautodiagnostics.com).
  4. How to Bench test a Starter Motor (Step by Step) (at: easyautodiagnostics.com).
{loadposition contact_form}]]>
troubleshootmyvehicle@hotmail.com (Abraham Torres-Arredondo) Nissan 3.0L, 3.3L, 3.5L Index of Articles Thu, 15 Aug 2013 21:25:34 +0000
Throttle Position Sensor Test [br](Nissan 3.3L Pathfinder, Xterra, Frontier) http://troubleshootmyvehicle.com/nissan/3.0L-3.3L-3.5L/throttle-position-sensor-tests-1 http://troubleshootmyvehicle.com/nissan/3.0L-3.3L-3.5L/throttle-position-sensor-tests-1 How to Test the Throttle Position Sensor (Nissan 3.3L)

As you're probably already aware, the throttle position sensor on your Nissan is two sensors in 1. One part of the assembly is the actual TP sensor and the other part is the idle switch.

Testing the throttle position sensor (TPS) to see if it has failed and causing a TPS diagnostic trouble code (DTC) is not hard.

In this tutorial, I'm gonna' show you how to troubleshoot the throttle position sensor (TPS) on your Nissan 3.3L Pathfinder (Frontier, XTerra or QX4), with a multimeter and in a step-by-step way.

I'm also gonna' show you how to adjust it after removing and replacing it (you can find these instructions on the last page of this tutorial).

Here are the contents of this tutorial at a glance:

  1. Symptoms of a Bad Throttle Position Sensor (TPS).
  2. How the Throttle Position Sensor (TPS) Works.
  3. Circuit (Wire) Descriptions of the TPS.
  4. START HERE: Troubleshooting the TP Sensor.
  5. TPS TEST 1: Testing the TPS Voltage Signal.
  6. TPS TEST 2: Verifying TPS Has Power.
  7. TPS TEST 3: Verifying TPS Has Ground.
  8. How to Adjust the Throttle Position Sensor Assembly.
  9. Where to Buy Your TP Sensor and Save.
  10. More Nissan 3.3L Test Tutorials.

If you need to test the idle switch part of the TP sensor assembly, the following tutorial will help: How to Test the Idle Switch (Nissan 3.3L Pathfinder, Xterra, Frontier).

Symptoms of a Bad Throttle Position Sensor (TPS)

Since the throttle position sensor is one of several sensors that your Nissan's fuel injection computer uses to calculate how much much fuel to inject, when it fails you're going to see several symptoms.

  1. Check engine light (CEL) shining nice and bright.
  2. Diagnostic trouble codes (DTC) stored in the PCM's memory:
    1. P0120: TP Sensor A Circuit Malfunction.
  3. Your Nissan Pathfinder (Xterra, Frontier) fails the state mandated emissions test.
  4. Bad gas mileage.
  5. Hard start and/or extended cranking time (after shut off).
  6. Black smoke coming out of the tailpipe.
  7. Hesitation when accelerating your Pathfinder down the road.

How the Throttle Position Sensor Works

As you're probably already aware, the throttle position sensor (TPS) on your 3.3L equipped Nissan Pathfinder (Frontier, Xterra or QX4) is attached to the throttle body and its job is to measure throttle plate angle.

In layman's terms, this means that the TPS is tasked with the job of measuring how much you step on or step off the accelerator pedal as you're driving the down the road.

This throttle plate angle information is then sent to your Nissan's fuel injection computer as a voltage DC signal.

To give you a few more specifics:

  1. As you step on the accelerator pedal,
    1. The throttle plate opens and the TP sensor measures how much and relays this to the PCM.
    2. The fuel injection computer injects more fuel.
  2. As you let your foot off the accelerator pedal,
    1. The throttle plate closes and the TP sensor measures how much and relays this to the PCM.
    2. The fuel injection computer injects less fuel.

Circuit (Wire) Descriptions of the TPS

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The throttle position sensor (TPS) on your 3.3L equipped Nissan Pathfinder (Frontier, Xterra or QX4) is located on the side of the throttle body.

As you can see in photo 2 of 2 (in the image viewer) the TP sensor has 2 connectors for a total of 6 wires coming out of both. This is due to the fact that the throttle position sensor is two sensors in one. One part of the assembly is the idle switch and the other part is the throttle position sensor itself.

The bottom brown connector connects to the TP sensor part and supplies it with power, ground, and relays the throttle angle voltage signal to the PCM. The gray connector connects to the idle switch part of the assembly.

To better understand how we're gonna' test the throttle position sensor (TPS), in this tutorial, I'm going to briefly describe each wire's job and how the sensor works.

TP sensor brown connector:

  1. The TP sensor is a 3 wire sensor.
    1. wire that connects to pin labeled with the number 1.
      1. Feeds ground to the TP sensor.
      2. ground is provided by the PCM (internally).
    2. wire that connects to pin labeled with the number 2.
      1. Feeds the throttle angle voltage signal to the PCM.
      2. This voltage signal varies depending on the amount of throttle plate opening.
    3. wire that connects to pin labeled with the number 3.
      1. Feeds power to the TP sensor.
      2. In the form of 5 Volts DC and is supplied only with Key On Engine Off (KOEO) or Key On Engine Running (KOER).
      3. Power comes directly from the PCM.

REMEMBER: The throttle position sensor (TPS), at closed throttle, produces a low voltage signal of around .5 Volts DC. As the throttle plate starts to open (as you step on the accelerator pedal and accelerate the engine), this .5 Volt signal starts to increase. At wide open throttle, the TP sensor will output about 4.5 Volts DC.

With this bit of information, let's move on to the next subheading...


START HERE: Troubleshooting the TP Sensor

The key to diagnosing the your 3.3L equipped Nissan Pathfinder (Frontier, Xterra or QX4)'s throttle position sensor (TPS) is to remember that:

  1. The TP sensor's voltage signal increases when the throttle plate opens
  2. The TP sensor's voltage decreases when the throttle plate closes.

So, the absolute best way to find out if the TPS has failed on your Nissan is by manually testing the TP sensor with a multimeter (while it's still on the throttle body and connected to its electrical connector).

Here's a summary of the 3 tests in this tutorial:

  1. Check the TP sensor's voltage signal with a multimeter.
    1. You'll be connecting your multimeter to the TP sensor connector's middle wire and then manually opening and closing the throttle to see if the TP sensor produces a varying DC voltage signal.
    2. TEST 1: Testing the TPS Voltage Signal.
  2. Verify that the TP sensor is getting power (if TEST 1 is failed).
    1. This is a simple multimeter test too.
    2. TEST 2: Verifying TPS Has Power.
  3. Verify that the TP sensor is getting ground (if TEST 1 is failed).
    1. This is a simple multimeter test too.
    2. TEST 3: Verifying TPS Has Ground.

TPS TEST 1: Testing the TPS Voltage Signal

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The very first thing that we're going to do is connect a multimeter to the wire that connects to the TPS pin labeled with the number 2 (this is the middle wire of the brown connector).

Once the multimeter is connected, we'll manually rotate the throttle plate to see if the throttle position sensor is creating a throttle angle signal.

While we're verifying the throttle angle voltage, we're gonna' gently tap the TP sensor with a screwdriver's handle to see if it affects the voltage output.

I'll explain everything in a step-by-step manner in the following instructions.

NOTE: To ensure the accuracy of your test, it's best to test the throttle position sensor (TPS) with the engine warmed up.

OK, let's start:

Part 1

  1. 1

    Place your multimeter in Volts DC mode and with the RED multimeter lead, probe the wire that connects to the TP sensor pin labeled with the number 2 in the image (in the image viewer above). This is the circuit that supplies the TP Signal to the PCM.

    If you don't have a multimeter or need to upgrade yours, check out my recommendation: Abe's Multimeter Recommendation (found at: easyautodiagnostics.com).

    NOTE: The throttle position sensor has to remain connected to its connector for this test to work (this is where a wire piercing probe comes in handy to get to the signal inside the wire. To see what one looks like, click here: Wire Piercing Probe Tool.)

  2. 2

    Ground the BLACK multimeter test lead on the battery negative terminal. Have you helper turn the Key On, but don't start the engine (this will power up the TP sensor).

  3. 3

    Your multimeter should report .4 to .9 Volts DC. If your multimeter doesn't, don't worry about it just yet, continue with the other steps.

Part 2

  1. 4

    Now, slowly open the throttle (by hand and from the engine compartment) while you observe the change in voltage numbers on your multimeter.

    For this test result to be accurate, you need to open the throttle by hand and not from inside the vehicle.

  2. 5

    As the throttle opens, the voltage numbers will increase. This increase in voltage should be smooth and without any gaps or skips. Once the throttle is wide open, your multimeter should read somewhere between 3.5 to 4.9 Volts DC.

  3. 6

    Now, slowly close the throttle. As the throttle is closing, you should see the voltage decrease smoothly and without any gaps or skips, to the exact same voltage you noticed in step 4.

Part 3

  1. 7

    OK, now you'll need someone to help you lightly tap on the throttle position sensor with the handle of a screw-driver (or something similar, and I want to emphasize the words ‘lightly tap') as you slowly open and close the throttle and observe the multimeter.

    If the TPS is bad, the tapping will cause the voltage numbers to skip or go blank. If the TPS is OK, the tapping will have no effect on the voltage numbers.

  2. 8

    Repeat step 7 several times to make sure of your multimeter test results.

Let's take a look at your test results:

CASE 1: Multimeter registered a smooth increase or decrease in voltage with no gaps. This test result tells you that the TP sensor on your 3.3L Nissan Pathfinder (Xterra, Frontier, QX4) is working correctly and that it's not malfunctioning at this time.

This test result also let's you know that the problem causing the P)120 trouble code is intermittent and not present at this point in time.

CASE 2: Multimeter DID NOT register a smooth increase or decrease in voltage, and you saw the voltage reading skip or go dead when tapping the TPS... then this means that the throttle position sensor (TPS) is BAD. Replace the throttle position sensor.

Go to Where to Buy Your TP Sensor and Save.

NOTE: After replacing the TPS, you'll need to adjust it. For the TPS adjustment instructions, go to: How to Adjust the Throttle Position Sensor Assembly.

CASE 3: Multimeter DID NOT register any voltage, this test result doesn't condemn the TPS as BAD just yet. Why? Because...

... the TPS may be missing either power or ground. So the next step is to check that the TPS is getting power, go to TPS TEST 2: Verifying TPS Has Power.


TPS TEST 2: Verifying TPS Has Power

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If you've reached this point, it's because in TEST 1 your 3.3L Nissan Pathfinder's (Xterra, Frontier, QX4) TP sensor did not produce a throttle angle signal.

There's a good chance that the cause of this test result is that the TP sensor is either missing power or ground.

So in this test we're going to check to see if the TP sensor is being fed with power on the wire that connects to the TP sensor pin labeled with the number 3.

As stated earlier, this power is in the form of 5 Volts DC and is feed to the TP sensor by the PCM.

NOTE: You can test for these 5 Volts DC with the TP sensor connected or disconnected to the TPS. I personally prefer to do this test with the TP sensor's connector unplugged.

This is what you'll need to do:

  1. 1

    Set your trusty multimeter's dial to Volts DC mode.

  2. 2

    Probe the wire that connects to your Nissan's TP sensor pin number 3, with the RED multimeter lead and an appropriate tool (like a Wire-Piercing Probe). The throttle position sensor's connector can be connected to the sensor or not when you probe this circuit.

    IMPORTANT If you probe the front of the TPS connector, be careful and don't damage the terminal. Damaging the terminal will require that you replace the connector.

  3. 3

    Connect the BLACK multimeter lead to a good and clean ground point on the engine or directly on the negative (-) battery terminal.

  4. 4

    When you've set up the test, have a helper turn the Key On Engine Off (KOEO).

  5. 5

    Your multimeter should display 4.5 to 5 Volts on its screen. OK, now let's interpret your test results below:

CASE 1: Multimeter registered 4.5 to 5 Volts, this confirms that the TP sensor is being fed with power (4.5 to 5 Volts DC).

The next step is to test the ground circuit of the throttle position sensor, go to TPS TEST 3: Verifying TPS Has Ground.

CASE 2: Multimeter DID NOT register 4.5 to 5 Volts, Recheck your connections and repeat the test. If your multimeter still doesn't register the 4.5 to 5 Volts DC...

... then you've just eliminated the TP sensor itself as bad. The two most likely reasons for this are: 1) an open short in the circuit or 2) the PCM may be fried (although a bad PCM is very rare).

Although it's beyond the scope of this article to test these two conditions, you have now eliminated the throttle position sensor (TPS) on your Honda as being the cause of the problem and/or the TPS diagnostic trouble code (DTC) lighting up the check engine light (CEL).

TPS TEST 3: Verifying TPS Has Ground

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So far you've confirmed that the TP sensor:

One: Is not producing a throttle angle voltage signal in TPS TEST 1.

Two: that it's getting power on the wire that connects to the TP sensor pin labeled with the number 2 of the brown connector in TPS TEST 2.

... the next step (and the purpose of this last test) is to see if it's being fed with ground by the wire that connects to TP sensor pin labeled with the number 1, in the illustration in the image viewer.

IMPORTANT: Remember, the PCM is the one that provides this ground internally... so be careful and don't accidentally or intentionally apply power (12 Volts) to this circuit or you'll fry the PCM.

OK, here are the test steps:

  1. 1

    With your multimeter still in Volts DC mode from TPS TEST 2.


  2. 2

    Probe the wire that connects to the TP sensor pin labeled with the number 1 in the photos with the BLACK multimeter lead. The TPS connector can be connected or not to the sensor.

    It's important that you do not probe the front of the connector or you run the risk of damaging the terminal.

  3. 3

    Now, with the RED multimeter lead, probe the battery positive (+) terminal.

  4. 4

    Once again, when everything is ready, have your helper turn the Key to its ON position but don't start the engine.

  5. 5

    If this circuit is OK and the PCM is providing a good path to ground, your multimeter will display 11 to 12 Volts.


CASE 1: Multimeter showed 11 to 12 Volts, this confirms that the PCM and the wire/circuit (that supply this ground) are OK.

All three test have confirmed that:

  1. Your 3.3L Pathfinder's (Frontier, Xterra, QX4) TPS is not providing a throttle plate angle signal when manually opening the throttle plate (TPS TEST 1).
  2. The TPS is being fed 5 Volts DC (TPS TEST 2).
  3. The TPS is being fed ground.

Therefore, you can conclude that the TP Sensor is BAD and needs to be replaced. The new TPS will need to be adjusted before you take your Nissan on the road and the following tutorial will show you how: Adjusting the Throttle Position Sensor Assembly.

CASE 2: Multimeter DID NOT show 11 to 12 Volts, Recheck your connections and repeat the test. If your multimeter still doesn't show the indicated voltage...

...then this indicates a problem with either the PCM (internal fault/problem) or an open in the wire between the TPS and the PCM itself.

Although testing these two conditions are beyond the scope of this article, you have now eliminated the throttle position sensor (TPS) on your Honda as being the cause of the problem and/or the TPS Diagnostic Trouble Code (DTC) lighting up the check engine light (CEL).


How to Adjust the Throttle Position Sensor Assembly

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If you have removed the throttle position sensor (TPS) and have replaced it, you'll need to adjust it to the correct specification.

Thankfully, adjusting the TPS isn't hard and can be done with the same multimeter you used to test it in the previous pages. In this section I'll show you how.

NOTE: The TP sensor assembly needs to be connected to its connectors for this adjustment to take place.

This is what you'll need to do:

  1. Turn the ignition switch to its Off position and make sure the TP sensor assembly is connected to its connectors.
  2. Turn the ignition switch to its On position but don't start the engine.
  3. Place your multimeter in Volts DC mode and:
    1. Connect the red multimeter lead to the wire that connects to the pin labeled with the number 2 (see the illustration in the image viewer above).
    2. Ground the black multimeter lead on the battery negative terminal.
    3. NOTE: Remember the throttle position sensor assembly must remain connected to its connectors through the entire adjustment.
  4. Adjust the TPS sensor by rotating it until the output voltage is within specification:
    1. Specification: .3 to .7 volts DC.
  5. Once the output voltage has reached the above voltage specification, tighten the TP sensor assembly mounting bolts.
  6. Once you're done, recheck the output voltage to make sure the TP sensor didn't move on you when you tightened the two bolts.

Where to Buy Your TP Sensor and Save

Just recently one of my cousins needed to buy a TP sensor for her 1998 Nissan Pathfinder and I was shocked and how much paid for it at our local auto parts store! After all, the TP sensor she bought is a no-name brand Chinese knock-off that she paid over $100 (US) for.

I didn't have the heart to tell her that she could've bought it a whole lot cheaper online, but I will tell you and I'll show you where to buy it. You can buy it here:

Not sure the TP sensor listed fits your particular Nissan? Don't worry, they'll make sure it fits your Honda, once you get to the TP sensor site, or they'll find the right one for you.

More Nissan 3.3L Test Tutorials

If this tutorial was helpful/informative, you can find a complete list of tutorials here: Nissan 3.0L, 3.3L, 3.5L Index of Articles.

Here's a sample of the tutorials you'll find there:

  1. How to Troubleshoot a No Start (Nissan 3.0L, 3.3L, 3.5L).
  2. How to Test Engine Compression (Nissan 3.0L, 3.3L, 3.5L).
  3. Mass Air Flow (MAF) Sensor Test 3.3L Frontier, Quest, Pathfinder, XTerra (at: easyautodiagnostics.com).
  4. How to Bench test a Starter Motor (Step by Step) (at: easyautodiagnostics.com).
{loadposition contact_form}]]>
troubleshootmyvehicle@hotmail.com (Abraham Torres-Arredondo) Nissan 3.0L, 3.3L, 3.5L Index of Articles Wed, 14 Aug 2013 21:28:52 +0000
How to Test the Starter Motor[br] (Nissan 3.0L Maxima) http://troubleshootmyvehicle.com/nissan/3.0L-3.3L-3.5L/how-to-test-the-maxima-starter-motor-1 http://troubleshootmyvehicle.com/nissan/3.0L-3.3L-3.5L/how-to-test-the-maxima-starter-motor-1 How to Test the Starter Motor (3.0L Nissan Maxima)

If you've been driving long enough, you know that eventually the starter motor is gonna' fail and when this happens, the most common symptom is that nothing happens when you turn the key (to crank and start the engine).

Well, the good news is that testing the starter motor is not hard to do and you don't need any expensive or exotic diagnostic tools to do it.

In this tutorial I'll help you test the starter motor on your Nissan Maxima, to see if it's causing the no crank condition you're currently experiencing.

Everything is explained in plain English and in a step-by-step way so that you can test it yourself.

Here are the contents of this article at a quick glance:

  1. Important Safety Precautions.
  2. Symptoms of a BAD Starter Motor.
  3. Tools Needed to Test the Starter Motor.
  4. STARTER TEST 1: Applying 12 Volts to the Starter Motor S Terminal.
  5. STARTER TEST 2: Verifying the Start Signal.
  6. STARTER TEST 3: Voltage Drop Testing the Battery (+) Cable.
  7. Related Test Articles.

Important Safety Precautions

Suggestion 1: Even though the photos I'm using in this tutorial show the starter motor off of the car... you'll be testing it on the car since the test in this tutorial is an On-Car test of the starter. The photos I'm using show it off of the vehicle just to make it easier to show you where to make your connections.

If you need to bench-test the starter motor, the following tutorial will help you: Bench Testing the Starter Motor (at: easyautodiagnostics.com).

Suggestion 2: To successfully test the starter motor... it's important that the battery be fully charged. Also, the battery cable terminals and battery posts must be clean and corrosion free.

Testing the starter motor with a discharged battery or corrosion on the battery cables/terminals will lead to false test results that'll have you replacing good parts that don't need replacement.

Suggestion 3: Use jack stands to keep your Nissan Maxima up in the air... don't trust the jack alone! Take all necessary safety precautions, like using jack stands to hold up the vehicle, wearing eye-protection (safety glasses), etc.

Suggestion 4: If you're vehicle has a standard transmission... make sure that it's out of gear and in neutral, and the parking brake is activated/on.

Symptoms of a BAD Starter Motor

When the starter motor goes BAD on your 3.0L Nissan Maxima, you'll see one of the following symptoms:

  1. Then engine doesn't turn over (crank) when you turn the key to start the engine.
  2. A jump start does not help. The vehicle's engine still refuses to crank.
  3. The battery has been charged and/or replaced and still your Nissan does not crank.
  4. When you turn the key to crank the engine, all you hear is a small knock and nothing else.

Although the above list is a not a very complete list of symptoms... the theme that runs thru' them, and any other related symptom, is that the engine will not turn over when you try to start it.

Tools Needed to Test the Starter Motor

You don't need expensive test equipment to test the starter motor on your 3.0L Nissan Maxima... but you do need a few things. These are:

  1. Jack.
  2. Jack stands.
  3. Remote starter switch.
    1. If you'd like to see what a remote starter switch looks like, you can follow this link: Actron CP7853 Remote Starter Switch.
    2. You can either buy this tool online or you can buy it at your local auto parts store (AutoZone, O'Reilly, Pepboys, etc.).
  4. Multimeter or a 12 Volt automotive test light.
    1. If you don't have a Multimeter or need to upgrade yours, check out my recommendation here: Abe's Multimeter Recommendation (at: easyautodiagnostics.com).
  5. A wire piercing probe.
    1. This tool is not an ‘absolute must have tool’ but I can tell you from experience that it makes it a whole lot easier to probe the S terminal wire for the Start Signal.
    2. If you'd like to see what this tool looks like, you find out more about it here: Wire Piercing Probe Tool Review (Power Probe PWPPPPP01).
  6. A helper.

As you can see... you don't need anything expensive. OK, let's turn the page and get starter with the first starter motor test.


STARTER TEST 1:
Applying 12 Volts to the Starter Motor S Terminal

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The very first thing I'm gonna' ask you to do, is to bypass the ignition switch and manually apply 12 Volts to the S terminal of the starter motor solenoid (identified with the letter S in the photo in the image viewer).

I use a wire piercing probe to pierce the S terminal wire and then I connect my remote starter switch to it and proceed from there. (to see what this tool looks like, go here: Wire Piercing Probe Tool Review (Power Probe PWPPPPP01)).

IMPORTANT: Before you perform this test... remove the key from the ignition switch to prevent the engine from accidentally starting.

OK, this is what you'll need to do:

  1. 1

    Jack up your Maxima and place on it jack stands. Don't trust the jack to keep your Maxima up in the air alone... use jack stands!

  2. 2

    Disconnect the battery negative terminal.

    You'll reconnect it back in one of the following steps, for now, it's a safety precaution as you set up the test.

  1. 3

    Attach one of the alligator-type terminals of the remote starter switch to the S terminal of the starter motor solenoid.

    Here's how I do it: I leave the S terminal wire connected to the starter motor. I then use a wire piercing probe to pierce the S terminal wire. I then connect the remote start switch to the wire piercing probe.

  2. 4

    Reconnect the negative battery cable to the battery negative post. Make sure that the battery cables and posts are clean.

  3. 5

    Connect the remaining alligator-type terminal of the remote starter switch to the battery positive post.

    Now, apply 12 volts to the S terminal wire of the starter motor starter solenoid with your remote starter switch. As you apply these 12 Volts (to the S terminal wire of the starter motor solenoid), you'll get one of two results:

    1. The starter will activate and will turn over the engine
    2. -OR-
    3. The starter motor won't do a thing.

Let's take a look at what your test results mean:

CASE 1: The starter motor cranked the engine. This test result let's you know that the starter motor is OK and functioning. This also tells you that the starter motor is NOT receiving the activation signal from the ignition switch.

The next step is to go to TEST 2 and see if the starter motor is getting the 12 Volt Start signal on the S terminal wire (circuit). Go to TEST 2: Verifying the Start Signal.

CASE 2: The starter motor DID NOT crank the engine. This usually means that your starter motor is BAD and needs to be rebuilt or replaced.

I suggest 2 more tests and these are make sure that the starter motor is getting its 12 Volt Start signal and to test the battery cable (that attaches to the starter motor starter motor) for corrosion. This can be accomplished very easily with a voltage drop test.

  1. Go to: TEST 2: Verifying the Start Signal.
  2. Go to: TEST 3: Voltage Drop Testing the Battery Cable.

STARTER TEST 2: Verifying the Start Signal

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In STARTER TEST 1 I asked you to bypass the ignition switch and apply 12 volts to the S terminal of the starter motor solenoid...

...In this test step, you're gonna' use a multimeter to see if the starter motor is being fed the Start Signal when you turn the key to start the engine.

You can use a multimeter or a 12 Volt automotive test light.

Ok, here's what you'll need to do:

  1. 1

    Lift the vehicle and place it on jack stands (if it isn't already up in the air). Now, while underneath the vehicle, connect the RED multimeter lead to the S terminal wire of the starter motor.

    The S terminal wire, of the starter solenoid, must remain connected to it's engine wiring harness connector for this test to work.

  2. 2

    Attach the BLACK multimeter lead to a clean and rust-free spot on the engine or on the vehicle frame.

    Here I'm going to recommend something to you: Use a battery jump start cable to ground the BLACK multimeter lead to a clean ground point on the engine. The reason why is that depending on how rusty and dirty the underneath of the vehicle... you may NOT be able to find a clean and rust-free spot to ground the multimeter's BLACK lead.

  3. 3

    Now, have your helper hop inside the vehicle and turn the key to crank the engine.

    The engine won't turn over, but the idea is to verify that the starter motor solenoid is getting the 12 Volt start signal from the ignition switch.

  4. 4

    Your multimeter is going to register one of two results: Either 10 to 12 Volts DC or no voltage at all.

    Alright, let's interpret the results of this test...

OK, let's make sense of the readings that your multimeter recorded in the test:

CASE 1: If your multimeter registered 10 to 12 Volts: This test result let's you know the starter solenoid is receiving the Start signal (crank signal).

This means that we can forget about the Safety Neutral Switch and the Ignition Switch being BAD. OK, now the next test is to do a very easy and simple voltage drop test. Go to TEST 3.

CASE 2: If your multimeter DID NOT register 10 to 12 Volts: This result exonerates the starter motor. Your starter motor is not BAD.

Here's the reason why... without this 10 to 12 Volt Crank Signal, the starter motor will not crank the engine. Now, although it's beyond the scope of this article to test the Neutral Safety Switch or the Ignition Switch, you have eliminated the starter motor and this means saving money by not buying a part your vehicle does not need.


STARTER TEST 3:
Voltage Drop Testing the Battery (+) Cable

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In this last test step, I'm gonna' ask you to do a voltage drop test on the battery cable that feeds battery power to the starter motor.

This voltage drop test will let us know if there's any hidden corrosion (on the battery positive cable) that's blocking battery power from reaching the starter motor (this condition is known as a voltage drop).

To further explain what a voltage drop is: a voltage drop is simply a condition in which something (in our case: unseen corrosion) blocks a lot of the battery power (voltage and current) from reaching its destination (the starter motor). When this happens, the starter motor will not be able to crank the engine in your 3.0L Nissan Maxima even though the battery is in a fully charged state.

OK, to get started, this is what you need to do:

  1. 1

    Place you multimeter in Volts DC mode. Attach the RED multimeter lead to the center of the positive battery terminal. If the positive battery post isn't clean... clean a spot right on the top of it. It's important that the multimeter lead make contact right in the center of the positive battery post.

    You may need two helpers for this test step, since someone will have to hold the RED multimeter lead onto the battery positive terminal and someone else will need to crank the vehicle while you perform the next step.

  2. 2

    With the BLACK multimeter lead, touch the center of the starter solenoid stud to which the big battery cable attaches to. You'll maintain the BLACK multimeter lead in this position throughout the next step.

  3. 3

    Now, have a helper turn the key to crank the engine from inside the vehicle. This is important, since a voltage drop test has to be done while the component in question is working (or trying to work).

  4. 4

    OK, if all is good (no voltage drop), your multimeter will register 0 Volts (.5 volts is still 0 Volts). If there's a voltage drop, your multimeter will register voltage (usually above 7 Volts DC.)

OK, now that the testing part is done... let's take a look at what your results mean:

CASE 1: Your multimeter registered 0 Volts (no voltage drop): This result indicates that the starter motor is receiving all of the battery voltage and Amperage it needs to crank the vehicle.

This also means that the starter motor is BAD, and here's why:

  1. In STARTER TEST 1 you confirmed that the starter motor doesn't work when you apply power to the S terminal wire of the starter motor solenoid.
  2. STARTER TEST 2 you confirmed that the starter motor is receiving the crank signal.
  3. In this test step you have confirmed that no voltage drop exists on the battery positive cable.

These 3 test results, taken together, indicate that the starter motor is BAD. Replacing the starter motor should solve your No Crank Condition.

I'm going to make two more recommendations to you:

  1. Before removing the starter motor, manually turn the engine using a 1/2 ratchet and the appropriate socket.. just to make sure the engine or the A/C Compressor have not locked up and causing the No Crank Condition.
  2.        -AND-
  3. Bench Test the starter motor after removing it. This is a super easy test to do and you can find this article by clicking here: Bench Testing the Starter Motor (at: easyautodiagnostics.com).

CASE 2: Your multimeter registered 5 Volts or more: This result tells you that a voltage drop does exist and this is not a good result.

The good news is that this can easily be corrected, since a voltage drop is always caused by some sort of corrosion issue on the battery positive cable or terminals or the battery positive post.

The solution is to thoroughly clean the battery positive post and the battery positive terminal (both the end that attaches to the battery positive post and the end the connects to the starter motor solenoid).

After cleaning, try cranking the engine. If it cranks and starts, no further testing is required.

Related Test Articles

You'll find a complete list of 3.0L Nissan Maxima tutorials in the following index: Nissan 3.0L, 3.3L, 3.5L Index of Articles.

Here's a small sample of the articles/tutorials you'll find in the index:

  1. How to Test Engine Compression (Nissan 3.0L, 3.3L, 3.5L).
  2. How to Troubleshoot a No Start (Nissan 3.0L, 3.3L, 3.5L).
  3. Mass Air Flow (MAF) Sensor Test 3.0L Nissan Maxima (1995-1999) (at: easyautodiagnostics.com).
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troubleshootmyvehicle@hotmail.com (Abraham Torres-Arredondo) Nissan 3.0L, 3.3L, 3.5L Index of Articles Wed, 13 Feb 2013 14:37:00 +0000
How to Troubleshoot a No Start [br](Nissan 3.0L, 3.3L, 3.5L) http://troubleshootmyvehicle.com/Nissan-3.0L-3.3L-3.5L-Index-of-Articles/how-to-test-a-no-start-condition.html http://troubleshootmyvehicle.com/Nissan-3.0L-3.3L-3.5L-Index-of-Articles/how-to-test-a-no-start-condition.html How to Troubleshoot a No Start (Nissan 3.0L, 3.3L, 3.5L)

What stinks about having your Nissan crank but not start, is that sooo many things can cause it. For example, the no start could be caused by a bad fuel pump, or a blown head gasket, or a busted timing belt, and unfortunately the list goes on.

In this tutorial, which is a primer on what can cause a cranks but does not start condition, I'll share some insights and tips, based from my actual experience, that will help you narrow down your troubleshooting efforts. Whether you Nissan V-6 is front wheel drive (FWD) or rear wheel drive (RWD) or a 4X4... the testing tips and suggestions will apply!

Here are the contents of this article at a quick glance:

  1. Difference Between a No Start and a No Crank Condition.
  2. No Start Condition Basics.
  3. No Start 1: Checking for Spark.
  4. No Start 2: Checking for Fuel.
  5. No Start 3: Checking Engine Mechanical Condition.
  6. No Start Summary.
  7. Related Test Articles.

Difference Between a No Start and a No Crank Condition

Since all of the articles I write are geared toward the Do-It-Yourself’er (DIY'er)... I want to clarify that a No Crank and a No Start Condition are not the same thing. Here's a brief description that'll help you make sense of this tutorial (and will help you find even more info online):

Cranks but Does Not Start Condition: Means that your Nissan's starter motor is cranking the engine but the engine is not starting. This is usually due to a fault in the ignition system, or in the fuel system, or there's an engine mechanical problem (like a thrown rod, etc.).

Does Not Crank Condition: Means that the engine is not cranking when you turn the key to crank the engine. In other words, the engine doesn't turn over at all. This is usually due to a bad starter motor, bad ignition switch, bad neutral safety switch, or the engine is locked up.

If your Nissan doesn't crank and you suspect the starter motor, here's a tutorial that'll help you test it: How to Test the Starter Motor (Nissan 3.0L, 3.3L).

No Start Condition Basics

OK, to start opening up about the most basic (and the most important) information you need to know to successfully diagnose the ‘cranks but does not start’ condition of your Nissan... is that the engine needs 3 things to start and run. These are:

  1. Air.
  2. Fuel.
  3. Spark.

When your Nissan Cranks but Does Not Start...it's because one of these 3 things is missing from the mix. It's as simple as this! I know, I know... I may be over-simplifying it all... but knowing that only one of three things is missing really helps to put the problem into perspective!

Now, knowing this means that when your or my Nissan doesn't want to start... my job (or your job if you're the one diagnosing/troubleshooting the problem) is to find out which of these 3 things is missing.

To get down into the nitty-gritty details- this means that troubleshooting the problem requires that you or I check for spark (with a spark tester), check fuel pressure, and if necessary, check the engine's health with a compression test.

I'll go into more specific details in the following headings:

1.)  Ignition System

  1. The Ignition System is the one tasked with creating and delivering spark to each of the 6 cylinders. Without spark, the engine will crank but Not Start.
  2. The Ignition System of the Nissan vehicles covered by this article use either distributor type system or a COP (Coil-on-Plug) ignition coil system. In a COP ignition coil system, each cylinder has its own ignition coil; thus eliminating the distributor entirely.
  3. In my experience, the most common component failures, of the Ignition System that cause a No Start No spark Condition are:
    1. Ignition control module (ICM) -most commonly known as the igniter (if distributor equipped).
    2. Ignition coil.
    3. Distributor cap (if distributor equipped).
    4. Distributor rotor (if distributor equipped).
  4. All of the above Ignition System components can be tested in a methodical way to find out exactly what has failed (if indeed something has).

2.)  Fuel System

  1. The Fuel System is the one responsible with supplying the engine with fuel.
  2. The Fuel System component that causes the majority of No Start No Fuel problems:
    1. Fuel pump relay.
    2. Fuel pump.
  3. The fuel pump can be tested to make sure it has really fried using a fuel pressure gauge.

3.)  Engine Mechanical System

  1. The components that are responsible for drawing in the air the engine needs are the: engine pistons, cylinder head valves, and all the other related components like: timing chain, etc.
  2. Although rare, internal engine mechanical problems can and do cause No Start Conditions.
  3. Possible internal/external engine problems are:
    1. Blown head gasket.
    2. Blown engine.
    3. Busted timing belt.

OK, the list of possible things that can go wrong looks pretty long... but it is rare to see (or have) two different components go BAD from two separate systems at the same time.

The cool thing is, is that there is a diagnostic strategy that you can use to figure out exactly what's wrong with your particular No Start problem. Let's find out more about it in the next subheading...


No Start 1: Checking for Spark

If your Nissan is suffering a cranks but does not start condition, my suggestion to you is to start by checking the ignition system. Specifically, what this means is that you should check that all cylinders are getting spark.

Testing for Spark can very easily and safely be done with a dedicated spark tester.

My suggestion, about testing for spark, applies whether your Nissan has a distributor-type ignition system or the more modern COP ignition coil system (in the Coil-on-Plug (COP) ignition coil system, you don't have a distributor anymore but 6 individual ignition coils sitting right on top of the spark plug).

If the Ignition System is the cause of the No Start, you're not gonna' see spark at any of the 6 spark plug wires or 6 COP ignition coils. If there is spark being fed to all cylinders... then you can eliminate the ignition system as the cause of the No Start condition and can move on to other tests (like testing fuel pressure).

Remember, the idea behind checking for spark is to see if all of the engine cylinders are getting spark. Here are the most common causes of a No spark result:

CASE 1: Spark was present in all cylinders This result tells you three very important things: 1.) the crank sensor is functioning correctly, 2.) the ignition control module (also known as the igniter or power transistor) is OK -this applies to distributor-type systems, and 3.) the ignition coil is good. You don't have to spend any time testing them or any money replacing them.

Your next step is to verify fuel pressure. Go to No Start 2: Checking Fuel.

CASE 2: Spark was NOT present in all of the cylinders (DISTRIBUTOR TYPE): This test result tells you without a doubt that the No Start Condition of your Nissan is due to a malfunction in the ignition system.

Now, with no spark in any of the engine cylinders, this what I would suggest:

  1. Check for spark directly on the ignition coil tower using a spark tester.
    1. This is the best way to test the distributor cap. The distributor cap and rotor are infamous for causing No Spark No Start Conditions.
    2. If you do get spark coming out of the ignition coil tower, you now know beyond a shadow of a doubt the distributor cap and rotor must be replaced.
  2. Test the ignition coil and ignition control module (also known as the: igniter or power transistor).
    1. If no spark is firing from the ignition coil, then the next step is to verify that the ignition control (igniter) is activating it. This is a pretty simple test.
  3. The following tutorial will give you some specific testing tips: Power Transistor Test & Ignition Coil Test 3.3L Nissan (1996-2004) (at: easyautodiagnostics.com).

CASE 3: Spark was NOT present in all of the cylinders (COP IGNITION COIL TYPE) This test result tells you without a doubt that the No Start Condition of your Nissan is due to a malfunction in the ignition system.

It's almost impossible for all 6 COP ignition coils to fail at the exact same time... so the most likely cause for this No Spark condition is a BAD crankshaft position sensor.

No Start 2: Checking for Fuel

Checking that the fuel pump is delivering fuel to the fuel injectors is not that hard on your Nissan (since you're able to tap into the rubber fuel pressure hose that connects to the fuel injector rail with a fuel pressure gauge and its appropriate adapter).

A BAD fuel pump will cause your Nissan to Crank but Not Start... since the fuel pump is the one responsible for supplying fuel to the fuel injectors.

The absolute best way to test the fuel pump is with a fuel pressure gauge... using any other method is not as accurate. Still, the other method that I've used to test for a lack of fuel... is spraying starting fluid into the throttle body and then having a helper crank the engine. If the engine starts... then I now know that I need to take a closer look at the fuel pump to see if it's fried or not.

When testing the fuel pump (with a fuel pressure gauge), you'll usually see one of two results:

CASE 1: fuel pressure is at specification. Not only does this result tell you that the fuel pump is OK but that the following components, that supply the fuel pump with power, are OK too:

  1. Fuel pump fuse.
  2. Fuel pump relay.

And so, there's no need to spend time testing them or money replacing them.

CASE 2: fuel pressure is not present. This usually means that the Pump has failed, but not always. I would recommend testing/checking the following before condemning the fuel pump:

  1. After verifying that no fuel pressure exists, check that the fuel pump is getting power by tapping into the power circuit that feeds the pump with 12 volts with a multimeter.
  2. Once you're tapped in, have a helper crank the engine while you observe your multimeter in Volts DC mode. If Voltage is present (12 Volts), then you have confirmed that the fuel pump fuse and fuel pump relay are working perfectly.
  3. Confirming power to the fuel pump (with a multimeter) also verifies that the fuel pump has failed and needs to be replaced.
  4. If no Voltage is present, as your helper cranks the engine, then the cause of No Fuel Condition is due to either a BAD fuse, fuel pump relay (known as the Main Relay).

No Start 3: Checking Engine Mechanical Condition

One of the most overlooked areas, when testing a hard to diagnose No Start, is the mechanical condition of your 3.0L, 3.3L, 3.5L Nissan vehicle.

Checking the engine mechanical condition usually means making sure that the timing belt hasn't broken (if equipped with a timing belt). Also, you may need to do: an engine compression test, a blown head gasket test, among a few tests to make sure that an internal engine problem is not the root cause of the cranks but does not start condition your vehicle is experiencing.

Here are some specific tips:

  1. When performing an engine compression test, what you're looking for is an average compression reading of NO LESS THAN 120 PSI across all or the majority of the engine cylinders.
  2. If you have one or just two readings that are under 90 PSI your Nissan vehicle will still start and run, albeit with a Misfire Condition.
  3. The following tutorial will help you do a compression test:
    1. How to Test Engine Compression (Nissan 3.0L, 3.3L, 3.5L).
  4. NOTE: A broken timing belt will cause all 6 cylinders to output 0 PSI compression.

No Start Summary

By this point, in this tutorial, you now know that the cranks but does not start condition of your 3.0L, 3.3L, or 3.5L equipped Nissan is due to a lack of one of the following:

  1. Spark.
  2. Fuel.
  3. Air (from a lack of cylinder compression).

Also, that you can verify if these things are missing or not... which means that you can: test for spark,... you can test the fuel pump (fuel pressure), ... and you can test the engine compression.

Thankfully, all of these things can be tested with simple tools... which leads me to the next talking point...

...To check the basics, you need tools. There's just no way around it. One of the analogies that I've always enjoyed repeating, about doing a job without the right tools is like trying to eat a bowl of soup with a fork.

So besides knowing what to test, you need tools to do those tests. You don't have to spend an arm and a leg, since you can buy a lot of diagnostics tools that are tailored for the pocket-books of the serious do-it-yourself-er. Here are some of the basic tools you'll need:

  1. Fuel pressure gauge.
  2. Spark tester.
  3. Compression gauge.
  4. Multimeter.

Most of these tools you can buy or rent for free (after you leave a cash deposit which you'll get back when you return the tool) at your local auto parts store (mainly AutoZone and O'Reilly Auto Parts). Or, if you want to save some bucks, you can buy them online.

Related Test Articles

You can find a complete list of articles here: Nissan 3.0L, 3.3L, 3.5L Index of Articles. Below, is a sample of articles you'll find in this index of articles:

  1. How to Test the Starter Motor (Nissan 3.0L, 3.3L).
  2. How to Test Engine Compression (Nissan 3.0L, 3.3L, 3.5L).
  3. Power Transistor Test & Ignition Coil Test 3.3L Nissan (1996-2004) (at: easyautodiagnostics.com).
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troubleshootmyvehicle@hotmail.com (Abraham Torres-Arredondo) Nissan 3.0L, 3.3L, 3.5L Index of Articles Sun, 20 Jan 2013 14:06:00 +0000
How to Test the Starter Motor[br] (Nissan 3.0L, 3.3L) http://troubleshootmyvehicle.com/Nissan-3.0L-3.3L-3.5L-Index-of-Articles/how-to-test-the-starter-motor.html http://troubleshootmyvehicle.com/Nissan-3.0L-3.3L-3.5L-Index-of-Articles/how-to-test-the-starter-motor.html How to Test the Starter Motor (Nissan 3.0L, 3.3L)

The starter motor can be tested on your 3.0L, 3.3L V-6 equipped Nissan Pathfinder (D21, Pick Up, or QX4) with some very simple tools to see if it's BAD or not.

In this tutorial I'll show you how test the starter motor in a step-by-step way. All the tests are explained in plain English and are accomplished with basic tools.

Here are the contents of this article at a quick glance:

  1. Important Safety Precautions.
  2. Symptoms of a BAD Starter Motor.
  3. Tools Needed to Test the Starter Motor.
  4. STARTER TEST 1: Applying 12 Volts to the Starter Motor S Terminal.
  5. STARTER TEST 2: Verifying the Start Signal.
  6. STARTER TEST 3: Voltage Drop Testing the Battery (+) Cable.
  7. Related Test Articles.

Important Safety Precautions

Suggestion 1: This is an On-Car Test of the starter motor on your 3.0L or 3.3L Nissan Pathfinder... so you don't need to remove it to test it. The photos I'm using show it off of the vehicle just to make it easier to show you where to make your connections.

Suggestion 2: It's important that the battery in your Nissan be fully charged to perform all of the tests. Also, the battery cable terminals and battery posts must be clean and corrosion free.

Suggestion 3: Use jack stands to keep your Nissan Pathfinder (D21, Pick Up, or QX4) up in the air... don't trust the jack alone! Take all necessary safety precautions, like using jack stands to hold up the vehicle, wearing eye-protection (safety glasses), etc.

Suggestion 4: If your vehicle has a standard transmission... make sure that it's out of gear and in neutral, and the parking brake is activated/on.

Symptoms of a BAD Starter Motor

When the starter motor goes BAD on your 3.0L, 3.3L Nissan Pathfinder (D21, Pick Up, or QX4), you'll see one of the following symptoms:

  1. Then engine doesn't turn over (crank) when you turn the key to start the engine.
  2. A jump start does not help. The vehicle's engine still refuses to crank.
  3. The battery has been charged and/or replaced and still your Nissan does not crank.
  4. When you turn the key to crank the engine, all you hear is a small knock and nothing else.

Although the above list is a not a very complete list of symptoms... the theme that runs thru' them, and any other related symptom, is that the engine will not turn over when you try to start it.

Tools Needed to Test the Starter Motor

You don't need expensive test equipment to test the starter motor on your 3.0L, 3.3L 6 cyl. Nissan Pathfinder... but you do need a few things. These are:

  1. Jack.
  2. jack stands.
  3. Remote starter switch.
    1. If you'd like to see what a remote starter switch looks like, you can follow this link: Actron CP7853 Remote Starter Switch.
    2. You can either buy this tool online or you can buy it at your local auto parts store (AutoZone, O'Reilly, Pepboys, etc.).
  4. Multimeter or a 12 Volt automotive test light.
    1. If you don't have a Multimeter or need to upgrade yours, check out my recommendation here: Abe's Multimeter Recommendation (at: easyautodiagnostics.com).
  5. A wire piercing probe.
    1. This tool is not an ‘absolute must have tool’ but I can tell you from experience that it makes it a whole lot easier to probe the S terminal wire for the Start Signal.
    2. If you'd like to see what this tool looks like, you find out more about it here: Wire Piercing Probe Tool Review (Power Probe PWPPPPP01).
  6. A helper.

As you can see... you don't need anything expensive. OK, let's turn the page and get starter with the first starter motor test.


STARTER TEST 1:
Applying 12 Volts to the Starter Motor S Terminal

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This first starter motor test will let you know right away if the starter motor is fried or not.

What we're gonna' do is to simply apply 12 volts to the starter motor solenoid S terminal using a remote starter switch.

NOTE: Getting to the starter motor solenoid S terminal (to manually apply 12 volts) can be quite a challenge... but not impossible. What I do is use a wire piercing probe to pierce the S terminal wire and then I connect my remote starter switch to it and proceed from there... I suggest you do the same (to see what this tool looks like, go here: Wire Piercing Probe Tool Review (Power Probe PWPPPPP01)).

OK, this is what you'll need to do:

  1. 1

    Jack up your Pathfinder (D21, Pick Up, or QX4) and place on it jack stands. Remember, to only way to gain access to the starter motor is from underneath your Pathfinder.

  2. 2

    Disconnect the battery negative terminal.

    You'll reconnect it back in one of the following steps, for now, it's a safety precaution as you set up the test.

  1. 3

    Attach a remote starter switch to the S terminal of the starter motor solenoid.

    This is easier said than done... so take your time and make sure the connection is on the S terminal of the starter motor solenoid.

    Also, in case you're wondering... you can leave the starter motor solenoid's S terminal wire connected to the engine's wiring harness connector or not, the test will work either way.

  2. 4

    Reconnect the negative battery cable to the battery negative post.

    Now, apply 12 volts to the S terminal wire of the starter motor starter solenoid with your remote starter switch. As you apply these 12 Volts (to the S terminal wire of the starter motor solenoid), you'll get one of two results:

    1. The starter will activate and will turn over the engine
    2. -OR-
    3. The starter motor won't do a thing.

Let's take a look at what your test results mean:

CASE 1: The starter motor cranked the engine. This test result let's you know that the starter motor is OK and functioning. It also tells you that the probable cause, of it not working when you turn the key to start the engine, is a lack of the 12 Volt Start signal on the S terminal of the starter motor solenoid.

The next step is to go to TEST 2 and see if the starter motor is getting the 12 Volt Start signal on the S terminal wire (circuit). Go to TEST 2: Verifying the Start Signal.

CASE 2: The starter motor DID NOT crank the engine. This usually means that your starter motor is BAD and needs to be rebuilt or replaced.

I suggest 2 more tests and these are make sure that the starter motor is getting its 12 Volt Start signal and to test the battery cable (that attaches to the starter motor starter motor) for corrosion. This can be accomplished very easily with a voltage drop test.

  1. Go to: TEST 2: Verifying the Start Signal.
  2. Go to: TEST 3: Voltage Drop Testing the Battery Cable.

STARTER TEST 2: Verifying the Start Signal

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As you may already know, when you turn the key to crank/start the engine... the starter motor gets 12 Volts on the S terminal wire of the starter motor solenoid. These 12 Volts are known as the Start signal.

So, in this test step, we're gonna' see if the starter motor solenoid is getting this Start signal on the S terminal wire. Since you already have your vehicle up on jack stands... this test won't be that hard to do.

You can use a multimeter or a 12 Volt automotive test light. Ok, here's what you'll need to do:

  1. 1

    Lift the vehicle and place it on jack stands (if it isn't already up in the air). Now, while underneath the vehicle, connect the RED multimeter lead to the S terminal wire of the starter motor.

    The S terminal wire, of the starter solenoid, must remain connected to it's engine wiring harness connector for this test to work.

  2. 2

    Attach the BLACK multimeter lead to a clean and rust-free spot on the engine or on the vehicle frame.

    Here I'm going to recommend something to you: Use a battery jump start cable to ground the BLACK multimeter lead to a clean ground point on the engine. The reason why is that depending on how rusty and dirty the underneath of the vehicle... you may NOT be able to find a clean and rust-free spot to ground the multimeter's BLACK lead.

  3. 3

    Now, have your helper hop inside the vehicle and turn the key to crank the engine.

    The engine won't turn over, but the idea is to verify that the starter motor solenoid is getting the 12 Volt start signal from the ignition switch.

  4. 4

    Your multimeter is going to register one of two results: Either 10 to 12 Volts DC or no voltage at all.

    Alright, let's interpret the results of this test...

OK, let's make sense of the readings that your multimeter recorded in the test:

CASE 1: If your multimeter registered 10 to 12 Volts: This test result let's you know the starter solenoid is receiving the Start signal (crank signal).

This means that we can forget about the Safety Neutral Switch and the Ignition Switch being BAD. OK, now the next test is to do a very easy and simple voltage drop test. Go to TEST 3.

CASE 2: If your multimeter DID NOT register 10 to 12 Volts: This result exonerates the starter motor. Your starter motor is not BAD.

Here's the reason why... without this 10 to 12 Volt Crank Signal, the starter motor will not crank the engine. Now, although it's beyond the scope of this article to test the Neutral Safety Switch or the Ignition Switch, you have eliminated the starter motor and this means saving money by not buying a part your vehicle does not need.


STARTER TEST 3:
Voltage Drop Testing the Battery (+) Cable

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Although you've probably already cleaned the battery cable terminals and the battery posts of corrosion... there's still a good chance that hidden corrosion (on the battery positive cable) is blocking battery power from reaching the starter motor (this condition is known as a voltage drop).

The absolute best way to eliminate this possibility, is with a simple voltage drop test of the battery positive cable that attaches to the large stud of the starter motor solenoid.

To further explain what a voltage drop is: a voltage drop is simply a condition in which unseen corrosion blocks a lot of the battery power from reaching the starter motor. When this happens, the starter motor will not be able to crank the engine in your Nissan 3.0L, 3.3L Pathfinder (D21, Pick Up, or QX4), even though the battery is in a fully charged state.

OK, to get started, this is what you need to do:

  1. 1

    Place you multimeter in Volts DC mode. Attach the RED multimeter lead to the center of the positive battery terminal. If the positive battery post isn't clean... clean a spot right on the top of it. It's important that the multimeter lead make contact right in the center of the positive battery post.

    You may need two helpers for this test step, since someone will have to hold the RED multimeter lead onto the battery positive terminal and someone else will need to crank the vehicle while you perform the next step.

  2. 2

    With the BLACK multimeter lead, touch the center of the starter solenoid stud to which the big battery cable attaches to. You'll maintain the BLACK multimeter lead in this position throughout the next step.

  3. 3

    Now, have a helper turn the key to crank the engine from inside the vehicle. This is important, since a voltage drop test has to be done while the component in question is working (or trying to work).

  4. 4

    OK, if all is good (no voltage drop), your multimeter will register 0 Volts (.5 volts is still 0 Volts). If there's a voltage drop, your multimeter will register voltage (usually above 7 Volts DC.)

OK, now that the testing part is done... let's take a look at what your results mean:

CASE 1: Your multimeter registered 0 Volts (no voltage drop): This result indicates that the starter motor is receiving all of the battery voltage and Amperage it needs to crank the vehicle.

This also means that the starter motor is BAD, and here's why:

  1. In STARTER TEST 1 you confirmed that the starter motor doesn't work when you apply power to the S terminal wire of the starter motor solenoid.
  2. STARTER TEST 2 you confirmed that the starter motor is receiving the crank signal.
  3. In this test step you have confirmed that no voltage drop exists on the battery positive cable.

These 3 test results, taken together, indicate that the starter motor is BAD. Replacing the starter motor should solve your No Crank Condition.

I'm going to make two more recommendations to you. 1.) Before removing the starter motor, manually turn the engine using a 1/2 ratchet and the appropriate socket.. just to make sure the engine or the A/C Compressor have not locked up and causing the No Crank Condition and 2.) Bench Test the starter motor after removing it. This is a super easy test to do and you can find this article by clicking here: Bench Testing the Starter Motor (at: easyautodiagnostics.com).

CASE 2: Your multimeter registered 5 Volts or more: This result tells you that a voltage drop does exist and this is not a good result.

The good news is that this can easily be corrected, since a voltage drop is always caused by some sort of corrosion issue on the battery positive cable or terminals or the battery positive post.

The solution is to thoroughly clean the battery positive post and the battery positive terminal (both the end that attaches to the battery positive post and the end the connects to the starter motor solenoid).

After cleaning, try cranking the engine. If it cranks and starts, no further testing is required.

Related Test Articles

You'll find a complete list of Nissan 3.0L, 3.3L tutorials in the following index: Nissan 3.0L, 3.3L Index of Articles.

Here's a small sample of the articles/tutorials you'll find in the index:

  1. Power Transistor Test & Ignition Coil Test Nissan 3.3L (1996-2004) (at: easyautodiagnostics.com).
  2. Engine Compression Test Nissan 3.0L, 3.3L, 3.5L.
  3. Mass Air Flow (MAF) Sensor Test 3.3L Frontier, Quest, Pathfinder, XTerra (at: easyautodiagnostics.com).
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troubleshootmyvehicle@hotmail.com (Abraham Torres-Arredondo) Nissan 3.0L, 3.3L, 3.5L Index of Articles Fri, 28 Dec 2012 14:37:00 +0000
How to Test Engine Compression[br] (Nissan 3.0L, 3.3L, 3.5L) http://troubleshootmyvehicle.com/Nissan-3.0L-3.3L-3.5L-Index-of-Articles/how-to-test-engine-compression.html http://troubleshootmyvehicle.com/Nissan-3.0L-3.3L-3.5L-Index-of-Articles/how-to-test-engine-compression.html How to Test Engine Compression (Nissan 3.0L, 3.3L, 3.5L)

A compression test can help you to nail down a hard to find misfire condition, since it's one of the most overlooked tests when diagnosing a rough idle or misfire condition.

The compression test will also let you know just how healthy (mechanically) the engine is on your Nissan 3.0L, 3.3L, 3.5L car, pick up, SUV or mini-van.

This article will walk you thru' the engine compression test and more importantly, I'll show you how to interpret the results of your compression test.

Here are the contents of this article at a quick glance:

  1. The ‘Dry’ Engine Compression Test.
  2. Interpreting the Results of the Engine Compression Test.
  3. The ‘Wet’ Engine Compression Test.
  4. Why an Engine Compression Test?
  5. Which Compression Tester Should I Buy?
  6. Related Test Articles.

The ‘Dry’ Engine Compression Test

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If your Nissan vehicle starts and runs, it's important to keep in mind that the engine compression test should be done with the engine slightly warmed up.

If your vehicle doesn't run, then don't worry about doing this test with the engine cold.

One last thing, this test is done with the engine cranking... so be carefull and take all necessary safety precautions, your safety is your responsibility

OK, let's get started:

  1. 1

    It's important the engine be slightly warmed up for this test, yet it can not be hot (technically: normal operating temperature) So, if the engine is completely cold, start her up and let it idle for no more than 15 minutes. If the engine has been running for a long period of time, let her cool down for about 1 hour.

  2. 2

    Disable the Ignition System.

    If your vehicle has a distributor, you can easily accomplish this by disconnecting all of the distributor's electrical connectors.

    If your vehicle does not have a distributor (equipped with 6 Coil-on-Plug Ignition Coils), then you'll disable the ignition system when you remove then in the next step.

  3. 3

    Remove all of the six spark plugs. Be careful and don't drop any of the spark plugs. Dropping them could cause their ceramic insulator to break... and this will cause a misfire.

    Important: If necessary (on distributor equipped vehicles), tag each spark plug wire before you disconnect them from the spark plugs... so that you'll know where they go when you re-install them.

  4. 4

    Hand-thread the engine compression gauge into the spark plug hole that you've chosen to test first. Do not use any type of tool to get it tight, hand tight is enough!

  5. 5

    Once everything is set, have your helper crank the car or mini-van till the needle on the compression tester gauge stops climbing. It normally takes about 10 seconds or engine cranking to get to this point. When the needle stops moving, you have reached the maximum compression pressure of that cylinder.

  6. 6

    Record the reading on a piece of paper along with the cylinder the reading belongs to. Now, repeat this exact same test on the remaining engine cylinders. The illustration in the image viewer will help you to identify what cylinders you're testing.

  7. 7

    Now, look at all of the four compression readings that you just wrote down. They should be within 15% of each other. Now, if you don't understand this 15% part, don't worry, the next part of this article will show you how to interpret what you have just done.

Interpreting the Results
of the engine compression test.

Now, I'm gonna' show you how to interpret all those compression pressure values you wrote down for each specific engine cylinder. Here's what you need to do with them:

  1. 1

    Grab a calculator and multiply the highest compression reading recorded by .15 (.15 is the decimal equivalent of 15%). So let's say, for the sake of this example, that the highest reading was 165 PSI (Pounds per Square Inch). Multiplying 165 by .15 gives us 25 (24.75 rounded off).

  2. 2

    Subtract 25 from the highest reading. In my example, the highest compression reading is 165... so subtracting 25 from this reading, I get: 140.

  3. 3

    So then, 140 PSI is the lowest possible compression reading that any one of the rest of the engine cylinders can have. Any compression reading below this.. and that engine cylinder will misfire.

Let me give you another, but more specific, example: Let's say that my 2002 Nissan 3.3L Frontier (or Nissan Quest, Pathfinder or whatever), produced the following compression readings:

  1. Cylinder #1 = 165 PSI
  2. Cylinder #2 = 85 PSI
  3. Cylinder #3 = 145 PSI
  4. Cylinder #4 = 160 PSI
  5. Cylinder #5 = 170 PSI
  6. Cylinder #6 = 165 PSI

The next step would be to apply the formula above and I get 145 PSI as the lowest possible reading (170 x .15= 25, 170-25= 145). So, now I know that cylinder #2 is the one causing the misfire!!


The ‘Wet’ Engine Compression Test

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The next step, after finding out that you do have one or more cylinders with low compression, is to add about 2 tablespoons of oil to them... and then retest their compression once more.

The Oil that you're gonna' add to the cylinder will help determine if the low cylinder pressure or pressures you recorded in the ‘Dry’ compression test are caused by worn piston rings or worn cylinder head valves.

Depending on whether the compression pressure rises (on your compression tester) or not, you'll be able to say that the problem lies in the Piston's rings or in the cylinder head valves.

This test... in which you add engine oil to the cylinders, is known as a ‘Wet’ compression test.

OK, this is what you need to do:

  1. 1

    Add a small amount of engine oil to the cylinder that reported low compression or no compression in the ‘Dry’ compression test.

    1. The amount should be about 1 to 2 tablespoons of oil.
  2. 2

    Install the compression tester onto the cylinder.

    1. Do not use any type of tool to tightened the compression tester... hand tight is fine.
  3. 3

    When all is set up, have your helper crank the engine.

  4. 4

    You'll get one of two results, either the compression value will go up (from the one you recorded before) or it will stay the same.

CASE 1: The compression value shot up.. This tells you that the piston compression rings are worn out and thus the problem is in the bottom end (block) of the engine in your 3.0L, 3.3L, or 3.5L Nissan.

CASE 2: The compression value stayed the same.. This confirms that the problem is in the cylinder head valves.

Why an Engine Compression Test?

An engine compression test is one of the most important tests to perform when trying to solve a hard to diagnose misfire condition / rough idle condition. If only one cylinder has below average compression (compared to the other 5 cylinders), that cylinder will not contribute to engine power... and you're gonna' feel it.

Also, no matter what you replace, the misfire condition or Misfire Codes (P0300, P0301, P0302, P303, P0304, P0305, P0306) will not go away! Unfortunately, the engine compression test is one of the most overlooked Misfire troubleshooting tests. Now, testing the compression of each cylinder is usually done after verifying that each cylinder is getting spark (this can be easily accomplished by using a spark tester).

Which Compression Tester Should I Buy?

There are lot of engine compression testers to choose from and many places to buy them. I'm gonna' make two recommendations to you:

1) Which one to buy:  The engine compression tester that I have always used is the Actron CP7827 compression tester Kit My only complaint about this engine compression tester is that it does not come with a case to store it in.

Engine Compression Gauge Testers

     

2) Where to buy:  You can go down to your neighborhood auto parts store to buy an engine compression tester, but you'll pay a whole lot more (usually double) than what you can buy it for from the ads that appear in the blue box above.

Related Test Articles

You can find more ‘How To Test’ articles for your 3.0L, 3.3L, 3.5L equipped Nissan car, pick up or mini-van at: 3.0L, 3.3L, 3.5L Nissan Index of Articles.

Here's a small sample of the tutorials you'll find in the index:

  1. How to Test the Starter Motor (Nissan 3.0L, 3.3L).
  2. Mass Air Flow (MAF) Sensor Test 3.0L Nissan Maxima (1995-1999) (at: easyautodiagnostics.com).
  3. Power Transistor Test & Ignition Coil Test 3.3L Nissan (1996-2004) (at: easyautodiagnostics.com).
  4. How to Test the Throttle Position Sensor (1996-1999 3.0L Maxima) (at: easyautodiagnostics.com).
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troubleshootmyvehicle@hotmail.com (Abraham Torres-Arredondo) Nissan 3.0L, 3.3L, 3.5L Index of Articles Mon, 20 Aug 2012 00:54:10 +0000
Power Transistor Test and Ignition Coil Test 3.3L Nissan Altima (1996-2004) http://troubleshootmyvehicle.com/Nissan-3.0L-3.3L-3.5L-Index-of-Articles/ignition-system-testing.html http://troubleshootmyvehicle.com/Nissan-3.0L-3.3L-3.5L-Index-of-Articles/ignition-system-testing.html Testing a No Start-No Spark or a Misfire Condition on your Nissan Mini-Van or Pick Up or SUV or the Mercury Villager (with the 3.3L V6 engine) is not difficult at all. No expensive tools or diagnostic equipment is needed, and this article will show you just how to do it step by step. With the tests in this article, you’ll be able to test and diagnose: A BAD Power Transistor, or a BAD Ignition Coil, or a BAD Distributor Cap, or BAD Spark Plug Wires on your Nissan vehicle. At the bottom of this page, you’ll find a complete list of Nissan and Infiniti models that this test article applies to. Symptoms of a BAD Transistor, Ignition Coil, Spark Plug Wires, or Dist. Cap If you’re Nissan SUV or mini-van is suffering a Misfire... the Check Engine Light (CEL) will be on to let you know that YES, there really is something wrong. Here are a couple of other symptoms your vehicle may experience with a Misfire Condition: Diagnostic Trouble Codes (DTC) stored in the Computer’s (PCM) memory: P0300, P0301, P0302, P0303, P0304, P0305, P0306 Misfire that does not light up the Check Engine Light (CEL). No Power. Idles Rough. BAD Gas Mileage. Black smoke coming out of the Tail Pipe. Rotten egg smell coming out of the Tail Pipe. Smell of unburned gasoline coming out of the Tailpipe. Won’t pass the State Emissions Test. If the Power Transistor or the Ignition Coil is BAD, then the most common symptom is that your vehicle will CRANK but not START and there will be no Spark at any of the Spark Plug Wires. Basic Nissan Ignition System Theory To be able to successfully diagnose a Misfire or No Start on your Nissan vehicle (whether it’ a pick up, SUV, or a mini-van) it’ll help to know how Spark is created and fed to the Engine Cylinders. This is what happens in a nutshell when you turn the key and crank the engine: The Crankshaft Position Sensor and Camshaft Position Sensors start to generate and feed their Signals to the vehicle’s PCM (Powertrain Control Module=Fuel Injection Computer). The PCM uses these Signals to know where each Piston is at in relation to its combustion cycle and with this info, the PCM knows when to start activating the Power Transistor, the fuel injectors and a host of other things to get your Nissan vehicle started. The Power Transistor is the Ignition Control Module (ICM) in the Nissan vehicles. The Power Transistor is located within the Distributor Assembly and is part of the Cam Sensor Assembly. So then, after receiving the Crank (CKP) and Cam (CMP) Signals, the PCM sends the Power Transistor a Triggering Signal that tells the Power Transistor exactly when to activate the Ignition Coil. The Power Transistor activates the Ignition Coil by opening and closing the Primary Current Circuit of the Ignition Coil... and as you may already be aware it’s this opening and closing action that makes the Ignition Coil Spark away. The Spark created by the Ignition Coil is fed to the Distributor Rotor directly by the Distributor Cap and then from there to each engine cylinder via a Spark Plug Wire. With the simple and easy tests presented in this test article you’ll be able to find the exact cause of your Nissan vehicle’s Misfire or No Start Condition (if it’s Ignition System related) and in the process save time and money.

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troubleshootmyvehicle@hotmail.com (Abraham Torres-Arredondo) Nissan 3.0L, 3.3L, 3.5L Index of Articles Mon, 20 Aug 2012 00:49:29 +0000