How To Test The Throttle Position Sensor (1.6L Sidekick, 1.6L Geo Tracker, 1.6L Chevy Tracker)

The throttle position sensor assembly, on your 1.6L Suzuki Sidekick (1.6L Geo Tracker or 1.6L Chevy Tracker) is 2 sensors in one. One part of the assembly is the throttle position sensor and the other is an idle switch.

In this tutorial I'm gonna' teach you how to test the throttle position part of the TPS assembly, to see if it's bad or not, using a simple multimeter. That's right... no scan tool needed!

The contents of this tutorial at a glance:

  1. Symptoms Of A Bad Throttle Position Sensor.
  2. TEST 1: Testing The Throttle Position Sensor Voltage Signal.
  3. TEST 2: Verifying Throttle Position Sensor Has Power.
  4. TEST 3: Verifying Throttle Position Sensor Has Ground.
  5. How to Adjust the 1.6L Sidekick TPS.
  6. Where To Buy Your Throttle Position Sensor And Save.

Symptoms Of A Bad Throttle Position Sensor

The throttle position part of the TPS assembly on your 1.6L Sidekick (Tracker) tracks the movement of the throttle plate and reports it to the PCM.

This is due to the fact that the throttle plate is connected to the accelerator pedal via the accelerator cable. So when you step on or off the accelerator pedal, the accelerator cable actuates the throttle plate to open or close.

As you're already aware, more air enters the engine as you step on the accelerator pedal and the throttle plate opens. As you let off of the accelerator pedal, the throttle plate closes and admits less air into the engine.

The info the TPS provides the PCM helps it to calculate engine load and either inject more or less fuel. This makes it one very important sensor! So, when it fails, your 1.6L Sidekick's engine performance is gonna' take a major hit!

When the TPS fails... you'll also see one or more of the following symptoms:

  1. Check engine light (CEL) illuminated on your 1.6L Sidekick's instrument panel.
  2. A TPS diagnostic trouble code (DTC) stored in the PCM's memory:
    1. P0121: Throttle Position Sensor Circuit Performance.
    2. P0122: Throttle Position Sensor Signal Voltage Low.
    3. P0123: Throttle Position Sensor Signal Voltage High.
  3. Your 1.6L Sidekick's fails the smog check (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 vehicle down the road.

Thankfully, the TPS can be tested without a scan tool and in the next section we'll start with the very first test.

TEST 1: Testing The Throttle Position Sensor Voltage Signal

How To Test The Throttle Position Sensor (1.6L Sidekick, 1.6L Geo Tracker, 1.6L Chevy Tracker)

As mentioned earlier, the TPS's job is to report the throttle plate angle to the PCM as you step on or off the accelerator pedal.

The throttle plate angle signal that the TPS creates is a Volts DC signal that you and I can see with a simple multimeter.

Reading the TPS voltage signal is done by tapping into the TPS signal wire with the multimeter in its Volts DC mode and then manually actuating the throttle plate to see the changes in the TPS voltage signal being read by the multimeter.

The TPS wire that we need to tap into is the gray (GRY) wire of the 4-wire TPS engine wiring harness connector.

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.)

OK, let's start:

  1. 1

    Place your multimeter in Volts DC mode and with the RED multimeter lead probe the GRY wire of the sensor's connector. The GRY wire is the one that connects to TPS pin #3 in the illustration above.

  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 a voltage between .2 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 4.5 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: 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.

I suggest one more check, and this is to see if the TPS is adjusted correctly. For this adjustment check, go to: How to Adjust the 1.6L Sidekick TPS.

CASE 2: The throttle angle voltage DID NOT increase (and/or decrease) as you opened and closed the throttle plate. This test result confirms that the TPS is behind the TPS trouble code lighting up the check engine light (CEL) on your 1.6L Sidekick (Tracker).

I'm gonna' suggest that you make sure that the TP sensor is getting both power and ground by performing the last two tests in this tutorial. To check that the TPS is getting power, go to: TEST 2: Verifying Throttle Position Sensor Has Power.

CASE 3: Multimeter DID NOT register any voltage, this test result doesn't condemn the TP sensor as BAD 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, go to TEST 2: Verifying Throttle Position Sensor Has Power.