Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Throttle Position (TP) Sensor G79/Accelerator Pedal Position Sensor 2 G185, checking
Special tools, testers and auxiliary items required
- Hand multimeter V.A.G 1526 or equivalent.
- Adapter Cable (121-Point) VAG1598/31.
- The Throttle Position (TP) Sensor G79/Accelerator Pedal Position Sensor 2 G185 is located in the accelerator pedal module and communicate the drivers intensions to the Engine Control Module (ECM) J623 completely independently of each other. Both sensors are located in the accelerator pedal module and replaced as an entire assembly.
Test requirements
- The fuses for engine electronics OK..
- The battery voltage must be at least 12.5 Volts.
- All electrical consumers such as, for example, lights and rear window defroster must be switched off.
- The parking brake must be applied, otherwise daytime running lights are switched on.
- On vehicles with an automatic transmission, the selector lever must be in position "P" or "N".
- If the vehicle is equipped with an A/C system, it must be switched off.
- The Ground (GND) connections between engine and body must be OK.
Procedure
- Remove left knee bolster → 68 - Interior Equipment Removal And Installation .
- Disconnect electrical harness connector - 2 -.
Checking voltage supply
- Switch ignition on.
- Using the Multimeter V.A.G. 1526 A or equivalent, check the following wiring connections for voltage.
| Harness connector Terminal | 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 ignition off.
If specified values are not obtained:
Checking wiring connections
- Connect Adapter Cable (121-Point) VAG1598/31 to wiring harness of the Engine Control Module (ECM) J623 ; the ECM is not connected. → Test box, connecting for wiring and component test .
- Using the Multimeter V.A.G. 1526 A or equivalent, check the following wiring connections for open circuit.
| Harness connector Terminal | Test box Socket |
|---|---|
| 1 | 72 |
| 2 | 73 |
| 3 | 36 |
| 4 | 35 |
| 5 | 33 |
| 6 | 34 |
Specified value: Wire resistance max 1.5 Ω.
If specification is not obtained:
- Check wiring for a short circuit to Battery positive (+) or an open circuit.
- If necessary, repair faulty wiring connection.
If no malfunction is detected in the wiring and if voltage supply was OK:
- Replace Throttle Position (TP) Sensor G79/Accelerator Pedal Position Sensor 2 G185. → Accelerator pedal module, removing and installing .
If no malfunction is detected in the wiring and if voltage supply was not OK:
- Replace Engine Control Module (ECM) J623. → Engine Control Module (ECM) J623, replacing .
Assembly is performed in reverse order of removal. Note the following:
- Install left knee bolster → 68 - Interior Equipment Removal And Installation .
Final procedures
After repair work, the following work steps must be performed in the mentioned sequence:
- Check DTC memory.
- If necessary, erase DTC memory.
- If DTC memory was erased, generate readiness code.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.