Throttle Position Sensor: Testing and Inspection

Throttle Position Sensor/Accelerator Pedal Position Sensor 2, Checking

Observe all safety precautions.

View clean working conditions.

Use only gold-plated terminals when servicing any component with gold-plated electrical harness connector terminals.

For wiring diagrams, component locations, and connector views, Refer to the applicable wiring diagram.

Special tools, testers and auxiliary items required

• multimeter.

• Wiring diagram

Test requirement

• The Motronic 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.

Start diagnosis

- Remove the drivers side storage compartment. Refer to the appropriate service information.

- Disconnect the Throttle Position (TP) Sensor (G79)/Accelerator Pedal Position Sensor 2 (G185) 6-pin electrical harness connector - 2 -.





Checking voltage supply and wiring

- Switch the ignition on.

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










- Switch the ignition off.

If the specification was not obtained:

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 Motronic Engine Control Module (ECM) (J623). Refer to the appropriate service information.

- Using a multimeter, check the Throttle Position (TP) Sensor (G79)/Accelerator Pedal Position Sensor 2 (G185) electrical harness connector terminals to the Motronic Engine Control Module (ECM) (J623) electrical connector T94 for an open circuit.










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 detected in the wiring and if the voltage supply was OK:

- Replace the Throttle Position (TP) Sensor (G79)/Accelerator Pedal Position Sensor 2 (G185). Refer to the appropriate service information.

If no malfunction is detected in the wiring and if the voltage supply was not OK:

- Replace the Motronic Engine Control Module (ECM) (J623). Refer to the appropriate service information.

- Install the drivers side storage compartment. Refer to the appropriate service information.

Final procedures

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

1. Check the DTC memory.

2. If necessary, erase the DTC memory.

3. If the DTC memory was erased, generate readiness code.