Accelerator Pedal Position Sensor: Testing and Inspection

Diagnostic Procedures

Throttle Position Sensor, Checking

Special tools, testers and auxiliary items required

• Multimeter (VAG1526) or Multimeter (VAG1715)

• Connector test kit (VAG1594)

• Wiring diagram

Test Prerequisites

• Fuses in E-box (plenum chamber, left) must be OK:





• Battery voltage must be at least 11.5 volts.

• All electrical consumers such as, lights and rear window defroster must be switched off.

• If vehicle is equipped with an A/C system, it must be switched off.

• Parking brake must be engaged or else daylight driving lights will be switched on.

• For vehicles with automatic transmission, selector lever must be in P.

• Ground (GND) connections between engine and chassis must be OK.

Function

Both the Throttle Position (TP) sensor (G79) and the Sender -2- for accelerator pedal position (G185) are located at the accelerator pedal and communicate the driver's intentions to the ECM completely independently of each other. Both sensors are stored in one housing.

Test Sequence

• When servicing terminals in the harness connector for the Throttle Position (TP) Sensor, use only gold-plated terminals.

- Remove footwell cover (driver's side).

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

Checking Voltage Supply

- Switch ignition on.

- Connect multimeter 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 specified values are not obtained:

- Check wires according to wiring diagram.

Wiring, Checking

- Connect test box to control module wiring harness , connect test box for wiring test.

- Check wires between test box and 6-pin connector for open circuit according to wiring diagram.





Terminal 1 + socket 72

Terminal 2 + socket 73

Terminal 3 + socket 36

Terminal 4 + socket 35

Terminal 5 + socket 33

Terminal 6 + socket 34 Wire resistance: max. 1.5 ohms

- Also check wires for short circuit to each other, to vehicle Ground (GND) and to B+.

Specified value: infinite ohms

- Erase DTC memory of Engine Control Module (ECM) , Diagnostic mode 4: Reset/erase diagnostic data.

- Generate readiness code.

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

- Replace Throttle Position (TP) sensor.

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.