How To Test The Throttle Position Sensor (1992-1995 1.5L Honda Civic)

The throttle position sensor (TPS) on your 1.5L Honda Civic is probably one of the easiest components of the fuel injection system to test.

You can easily find out if it's bad or not in 2 simple multimeter tests. The cool thing is that you don't need a scan tool to do it.

In this tutorial, I'll show you how in a step-by-step way. Moreover, you don't need to remove the TPS assembly from the throttle body to test it.

You can find this tutorial in Spanish here: Cómo Probar El Sensor TPS (1.5L Honda Civic) (at: autotecnico-online.com).

APPLIES TO: This tutorial applies to the following vehicles:

• 1.5L Honda Civic: 1992, 1993, 1994, 1995.
• 1.5L Honda Civic Del Sol: 1993, 1994, 1995.

TPS SENSOR -WHAT DOES IT DO?:

• What Does The Throttle Position Sensor Do? (1992-1995 1.5L Honda Civic).

MAP SENSOR DIAGNOSTIC TESTS:

• How To Test The MAP Sensor (1992-1995 1.5L Honda Civic).

Symptoms Of A Bad Throttle Position Sensor

As I'm sure you're already aware, the throttle plate opens and closes as you step on or off the accelerator pedal. Its the TP sensor's job to report this throttle plate angle to your Civic's fuel injection computer.

This throttle plate angle signal is a voltage signal that increases from about 0.4 Volts DC to about 4.5 Volts DC at the throttle plate's wide open throttle (WOT) position.

You can learn more about what the TP sensor does here: What Does The Throttle Position Sensor Do? (1992-1995 1.5L Honda Civic).

Since the TPS is a critical sensor for the engine management, when it fails, you'll see the following trouble code lighting up the check engine light on your 1.5L Civic's instrument cluster:

• Code 7: Throttle Position Sensor.

Besides a Code 7, you're going to see one or more of the following symptoms.

• Bad gas mileage.
• Hard start: You've got to crank the engine a long time to get it to start.
• Hesitation under load: The engine stumbles or bogs when you hit the gas.
• Unstable idle: RPM hunts, flares, or drops unexpectedly.
• Stalling: The engine can cut off coming to a stop or when the throttle closes.

TPS Circuit Descriptions

The throttle position sensor on your 1.5L Honda Civic is a 3-wire sensor. Each circuit (wire) has a specific job to do and in the table below, you'll find a brief description of each:

Pin	Wire	Description
1	Yellow with white stripe (YEL/WHT)	5 Volts
2	Red with blue stripe (RED/BLU)	Throttle Position Signal
3	Green with white stripe (GRN/WHT)	Ground

Where To Buy The TPS And Save

If you find, after testing the Civic's throttle position sensor, that it's fried; take a look at the links below. I think they'll save you some bucks:

NOTE: If you're not sure if the above TPS fit your particular 1.5L Civic don't worry. Once you get to the site, they'll make sure the sensor is the right one, if not, they'll find you the right one.

TEST 1: Testing The TPS Voltage Signal

OK, the first test is to verify that the TPS, on your 1.5L Civic, is producing a throttle plate position voltage signal that increases as you open the throttle plate and decreases as you close it.

If your Honda Civic's TP sensor is defective then its throttle plate voltage signal will stay fixed at a single voltage value.

To be a bit more specific, the voltage value your multimeter reports WILL NOT increase to about 4.5 Volts as you open the throttle plate NOR will it decrease to about 0.4 Volts as you release it.

If you don't have a multimeter and need to buy one, this is the one I use and recommend: Tekpower TP8268 AC/DC Auto/Manual Range Digital Multimeter (at: amazon.com).

IMPORTANT: You'll need to use a wire-piercing probe (on the signal wire) or a back-probe (on the connector) to measure the TP signal voltage. If you don't have either tool, this is what I use and recommend: Goupchn 4mm Banana to Banana Plug Test Leads Kit (Amazon affiliate link).

You can see this test step performed in this YouTube video here: How To Test The TPS (1997, 1998, 1999, 2000, 2001 2.0L Honda CR-V)   (NOTE: Although this video applies to the 1997-2001 2.0L Honda CR-V, the test procedure itself is the same for the 1993-2005 1.6L Honda Civic).

Here are the steps:

1. 1

   Set your multimeter to Volts DC mode.

2. 2

   Connect the black multimeter test lead on the battery negative (-) terminal.

3. 3

   Connect the red multimeter test lead to the middle wire of the sensor's connector.
   
   The middle wire connects to pin #2 in the illustration above and is the red with blue stripe (RED/BLU) wire.
   
   NOTE: The TP sensor must remain connected to its 3-wire connector to read the TP signal.

4. 4

   Have your helper turn the key to the ON position, but don't start the engine (this will power up the TP sensor).

5. 5

   Your multimeter should report a voltage between 0.2 to 0.9 Volts DC.
   
   If your multimeter doesn't, don't worry about it just yet, continue with the other steps.

Part 2

1. 6

   Now, slowly open the throttle plate (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. 7

   As the throttle plate 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 4.5 Volts DC.

3. 8

   Now, slowly close the throttle plate.
   
   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. 9

   Have your helper 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. 10

   Repeat step 9 several times to make sure of your multimeter test results.

Let's take a look at your test results:

CASE 1: The throttle angle voltage increased and decreased as you opened and closed the throttle plate. This test result confirms that the TP sensor is OK and not defective.

CASE 2: The throttle angle voltage DID NOT increase (and/or decrease) as you opened and closed the throttle plate. This test result confirms the throttle position sensor trouble code lighting up the check engine light on your 1.5L Honda Civic.

Your next step is to make sure that the TP sensor is getting both power and Ground. To check for power on the, go to: TEST 2: Making Sure The TPS Is Getting 5 Volts.

CASE 3: The multimeter DID NOT register any voltage. This test result doesn't condemn the TP sensor as defective just yet. Why? Because the TP sensor may be missing either power or Ground.

So the next step is to check that the TP sensor is getting power and Ground, go to: TEST 2: Making Sure The TPS Is Getting 5 Volts.

TEST 2: Making Sure The TPS Is Getting 5 Volts

If your 1.5L Honda Civic's TP sensor failed TEST 1, then the next step is to make sure it's getting power since without it, the sensor won't produce an increasing/decreasing voltage signal.

The yellow with white stripe (YEL/WHT) wire, which connects to female terminal 3 of the TPS connector, is the one that supplies 5 Volts.

To confirm that the YEL/WHT wire is delivering this voltage, we'll do a simple multimeter voltage test at terminal 3.

You can see this test step performed in this YouTube video here: How To Test The TPS (1997, 1998, 1999, 2000, 2001 2.0L Honda CR-V)   (NOTE: Although this video applies to the 1997-2001 2.0L Honda CR-V, the test procedure itself is the same for the 1992-1995 1.5L Honda Civic).

NOTE: This test requires probing the front of the female terminal on the TP sensor's 3-wire connector. Be careful not to damage the terminal with the multimeter test lead, or you'll end up having to replace the connector.

OK, this is what you need to do:

1. 1

   Disconnect the TP sensor from its 3-wire connector.

2. 2

   Connect the black multimeter test lead to the battery negative (-) post.

3. 3

   Set the multimeter to Volts DC mode.

4. 4

   Turn the key to the ON position but don't crank or start the engine.

5. 5

   Gently probe female terminal 3 of the TPS connector with the red multimeter test lead.
   
   NOTE: Make sure that terminal 3 corresponds to the YEL/WHT wire.

6. 6

   The multimeter should register 4.5 to 5 Volts DC.

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

CASE 1: The multimeter confirms the TPS is getting power. Great, this is what we need to see.

The next step is to make sure the TP sensor is getting Ground from the FI computer. Go to: TEST 3: Making Sure The TPS Is Getting Ground.

CASE 2: The multimeter is not registering any voltage. This tells you that the TP sensor isn't getting power and without it, it's not gonna function.

The most likely cause of this missing voltage is an open-circuit problem in the 5V supply wire between the TPS connector and the fuel injection computer.

Your next step is to find out what's causing this missing voltage and restore it to the circuit.

TEST 3: Making Sure The TPS Is Getting Ground

So far, you've confirmed that:

• TEST 1: The TP sensor's voltage doesn't change when you open/close the throttle plate.
• TEST 2: It's getting 4.5 to 5 Volts DC.

In this last test section, we'll see if the green with white stripe (GRN/WHT) wire, which connects to terminal 1 of the TPS connector, is delivering Ground to the TP sensor.

IMPORTANT: Your Honda Civic's fuel injection computer is the one that feeds Ground to the throttle position sensor (TPS). Be careful and don't short the Ground wire (circuit) to battery voltage or you'll fry the computer. The multimeter voltage test I'm outlining below is a safe way to check for Ground.

This is what we need to do:

1. 1

   Disconnect the TP sensor from its 3-wire connector.

2. 2

   Connect the red multimeter test lead to the battery positive (+) post.

3. 3

   Set the multimeter to Volts DC mode.

4. 4

   Turn the key to the ON position but don't crank or start the engine.

5. 5

   Gently probe female terminal 1 of the TPS connector with the black multimeter test lead.
   
   NOTE: Confirm that terminal 1 corresponds to the GRN/WHT wire.

6. 6

   The multimeter should register 10 to 12 Volts DC if Ground is present.

Let's interpret your test result:

CASE 1: The multimeter registers 10 to 12 Volts. This confirms the sensor is getting Ground from your Civic's fuel injection computer.

Now, you can confidently conclude that the TPS is bad only if:

• You have confirmed that the TPS voltage signal IS NOT increasing/decreasing while opening/closing the throttle plate (in TEST 1).
• You have confirmed that the TPS is getting 5 Volts (TEST 1) and Ground (this test section).

If you're ready to replace the TPS sensor on your 1.5L Honda Civic, these are the two sensors I recommend from known automotive brands I don't hesitate to recommend:

• Dorman 911-753 Throttle Position Sensor (Amazon affiliate link).
• APDTY 022864 Throttle Body Position Sensor (Amazon affiliate link).

CASE 2: The multimeter is not registering any voltage. This tells you that the TP sensor isn't getting Ground and without it, it's not gonna function.

The most likely cause of this missing Ground is an open-circuit problem in the Ground supply wire between the TPS connector and the fuel injection computer.

Your next step is to find out what's causing this lack of Ground and restore it to the circuit.

More 1.5L Honda Civic Tutorials

You can find a complete list of 1.5L Honda Civic diagnostic test tutorials in this index:

• 1.5L Honda Civic Index of Articles.

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

• How To Test The MAP Sensor (1992-1995 1.5L Honda Civic).
• How To Test The PGM-FI Main Relay (1992-1995 1.5L Honda Civic).
• How To Test Engine Compression (1992-1995 1.5L Honda Civic).
• How To Test The Fuel Pump In 2 Tests (1992-1995 1.5L Honda Civic).
• How To Test The Igniter, Ignition Coil Accord, Civic, CRV, and Odyssey (at easyautodiagnostics.com).