Throttle Position Sensor: Testing and Inspection

Diagnostic Procedures

Throttle Position Sensor/Accelerator Pedal Position Sensor 2, Checking

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram

Test requirement

• The Motronic Engine Control Module (ECM) ( J220) 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 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

- Remove the drivers side storage compartment. Refer to the Repair 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 specified value 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) ( J220). Refer to the Repair 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) (J220) electrical connector T121 for an open circuit.









Specified value: 1.5 ohms max.

If the specified value was Not obtained:

- Check the wiring for a short circuit to each other, Battery (+) or Ground or high resistance.

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

- If necessary, repair the faulty wiring connection.

If no fault is detected in the wiring and the voltage supply was OK:

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

If no fault is detected in the wiring and the voltage supply was Not OK:

- Replace the Motronic Engine Control Module (ECM) (J220). Refer to the Repair Information.

- Install the drivers side storage compartment.

Final procedures

After the 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 Modes 01 - 09.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.