Throttle Position (TP) Sensor G79 / Accelerator Pedal Position Sensor 2 G185 , Checking

Throttle Position (TP) Sensor G79 / Accelerator Pedal Position Sensor 2 G185 , Checking (Engine Code AMB)

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

NOTE: 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 sequence
- Remove the drivers side storage compartment.







- 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.

Throttle Position (TP) Sensor G79 / Specified
Accelerator Pedal Position Sensor 2 G185 value
electrical harness connector terminal
1 to Ground (GND) about 5 V
1 to 5 about 5 V
2 to Ground (GND) about 5 V
2 to 3 about 5 V

- 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) J220.







- 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 for an open circuit.

Throttle Position (TP) Sensor Motronic Engine Control
G79/Accelerator Pedal Module (ECM) J220
Position Sensor 2 G185 electrical electrical connector test
harness connector terminals box sockets
1 72
2 73
3 36
4 35
5 33
6 34

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, lose 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.

If no malfunction is detected in the wiring and if the voltage supply was not OK:
- Replace the Motronic Engine Control Module (ECM) J220.
- 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. Diagnostic Mode 03 - Read DTC Memory
2. If necessary, erase the DTC memory. Diagnostic Mode 04 - Erase DTC Memory
3. If the DTC memory was erased, generate readiness code.

- End of diagnosis.