Throttle Position Sensor: Testing and Inspection

Throttle Position (TP) Sensor, Checking

NOTE: Use only gold-plated terminals when servicing terminals in the harness connector.

Function
Both the Throttle Position (TP) Sensor -G79- and Accelerator Pedal Position Sensor 2 - G185- are located at the accelerator pedal module and communicate the driver's intentions to the ECM completely independently of each other. Both sensors are stored in one housing.

Recommended special tools and equipment
- V.A.G 1526 multimeter or V.A.G 1715 multimeter
- V.A.G 1594 connector test kit
- Wiring diagram

Test requirements
- Fuses on E-box in engine compartment, left side, must be OK.

NOTE: Fuses on this fuse holder are labelled "SB" in the wiring diagram.







- Fuses on fuse holder in instrument panel, left side, must be OK.

NOTE: Fuses on this fuse holder are labelled "SC" in the wiring diagram.

- Battery voltage must be at least 11.5 Volts.
- All electrical consumers such as, for example, lights and rear window defroster must be switched off.
- Ground (GND) connections between engine and chassis must be OK.
- Ignition switched off.

Test sequence







- Remove steering column cover -arrows-.







- Disconnect 6-pin connector -arrow- from Throttle Position (TP) Sensor.

Checking voltage supply
- Switch ignition on.







- Connect multimeter with test leads to the following connector terminals for voltage measurement.
Terminal 1 + Ground (GND)
Terminal 1 + 5
Terminal 2 + Ground (GND)
Terminal 2 + 3

Specified value: at least 4.5 V

- Switch ignition off.

If there is no malfunction in voltage supply:
- Check wires to Engine Control Module (ECM) according to wiring diagram.

Checking wires to Engine Control Module (ECM)
- Connect test box to 94-pin connector of wiring harness, connecting test box for wiring test.

Engine Control Module (ECM) is not connected.







- Check wires between test box and 6-pin connector to Engine Control Module (ECM) for open circuit according to wiring diagram.
Terminal 1 + socket 58
Terminal 2 + socket 80
Terminal 3 + socket 78
Terminal 4 + socket 79
Terminal 5 + socket 56
Terminal 6 + socket 57

Wire resistance: max. 3.0 ohms

- Also check wires for short circuit to each other.

Specified value: infinity ohms

- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 04 - Erase DTC Memory
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

If no malfunction is detected in the wiring and if the voltage supply was OK:
- Replace accelerator pedal module with Throttle Position (TP) Sensor -G79- and Accelerator Pedal Position Sensor 2 -G185-.
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 04 - Erase DTC Memory
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

If no malfunctions are found in wires and there was no voltage:
- Replace Engine Control Module (ECM) -J623-.