Throttle Position Sensor: Testing and Inspection

Throttle Position Sensor G79 and Accelerator Pedal Position Sensor 2 G185, Checking

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram

Test requirement

• The Engine Control Module (ECM) ( J623) fuses OK.

• Battery voltage at least 12.5 volts.

• All electrical consumers such as, lights and rear window defroster, switched off.

• Vehicles with automatic transmission, shift selector lever into position " P" or "N".

• A/C switched off.

• Ground (GND) connections between engine/transmission/chassis OK.

• Use only gold-plated terminals when servicing the electrical harness connector terminals in Throttle Position (TP) Sensor (G79 )/Accelerator Pedal Position Sensor 2 (G185).

Test procedure

- Perform a preliminary check to verify the customers complaint. Refer to => [ Preliminary Check ] Preliminary Check.

Start diagnosis

- Using a screwdriver, remove the steering column cover - arrows -.





- Disconnect the Throttle Position (TP) Sensor ( G79)/Accelerator Pedal Position Sensor 2 (G185 ) electrical harness connector - 2 -.





Checking voltage supply

- Switch the ignition on.

- Using a Multimeter, check the following wiring connections for voltage.









- Switch the ignition off.

If the specified values were obtained:

- Replace the Throttle Position (TP) Sensor (G79 )/Accelerator Pedal Position Sensor 2 (G185).

If any of the specified values were not obtained:

Checking wiring

If the manufacturers test box is being used. Perform the following step.

- Install the test box.

If the manufacturers test box is not being used. Perform the following step.

- Remove the Engine Control Module (ECM) (J623). Refer to => [ Engine Control Module J623, Replacing ] Engine Control Module J623, Replacing.

- Using a Multimeter, check the Throttle Position (TP) Sensor (G79)/Accelerator Pedal Position Sensor 2 (G185) electrical harness connector terminals to the Engine Control Module (ECM) (J623) electrical connector T121 for resistance.









Specified value: 1.5 ohms max.

If the specification is not obtained:

- Check the wiring for a short circuit to each other, Battery (+), and Ground (GND).

- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

- If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring and the voltage supply was OK:

- Replace the Throttle Position (TP) Sensor (G79 )/Accelerator Pedal Position Sensor 2 (G185).

If no malfunction is found in wiring:

- Erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Mode 04 - Erase DTC Memory.

- Perform a road test to verify repair.

If the DTC does not return:

Repair complete, Generate readiness code. Refer to => [ Readiness Code Description ] Readiness Code Description.

- End diagnosis.

If the DTC returns and no malfunction is found in the wiring and voltage supply was OK:

- Replace the Engine Control Module (ECM) (J623 ). Refer to => [ Engine Control Module J623, Replacing ] Engine Control Module J623, Replacing.

- Assembly is performed in the reverse of the removal.

Final procedures

After repair work, the following work steps must be performed in the following sequence:

1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Mode 03 - Read DTC Memory.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Mode 04 - Erase DTC Memory.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Readiness Code.

End of diagnosis