Throttle Position (TP) Sensor G79 / Accelerator Pedal Position Sensor 2 G185 , 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 (GND) connections between engine/transmission/chassis OK.

Test procedure 

• Perform a preliminary check to verify the customers complaint. Refer to → Motronic Engine Control Module (ECM) J220 , replacing 

Start diagnosis 

• Remove the drivers side footwell cover.
• Disconnect the Throttle Position (TP) Sensor G79 / Accelerator Pedal Position Sensor 2 G185 6-pin electrical harness connector.

Checking voltage supply and wiring 

• Switch the ignition on.

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

Throttle Position (TP) Sensor G79 / Accelerator Pedal Position Sensor 2 G185 electrical harness connector terminals	Specified value
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 Test Box 105 Pin VAG1598/31. Refer to 24 MULTIPORT FUEL INJECTION (MFI) for Engine Code AWD and 24 MULTIPORT FUEL INJECTION (MFI) for Engine Codes AWP and AWW .

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

• Remove the Motronic Engine Control Module (ECM) J220. Refer to → Motronic Engine Control Module (ECM) J220 , replacing  .

• 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.

Throttle Position (TP) Sensor G79 / Accelerator Pedal Position Sensor 2 G185 electrical harness connector terminals	Motronic Engine Control Module (ECM) J220 electrical harness connector T121 terminals or test box sockets
1	72
2	73
3	36
4	35
5	33
6	34

Specified value: 1.5 Ω 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. Refer to 20 - FUEL SUPPLY .

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

• Erase the DTC memory. Refer to → Diagnostic Mode 04: Reset/delete diagnostic data 
• Perform a road test to verify repair.

If the DTC does not return:

Repair complete, Generate readiness code. Refer to →Readiness Code  .

• End diagnosis.

If the DTC does return and no malfunction is detected in the wiring and the voltage supply was OK:

• Replace the MFI Engine Control Module (ECM) J220. Refer to → Motronic Engine Control Module (ECM) J220 , replacing  .
• Assembly is performed in the reverse of the removal.

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.

End diagnosis