Throttle Position Sensor & Sender Accelerator Position, Check

Throttle Position (TP) Sensor -G79- And Sender -2- For Accelerator Pedal Position -G185-, Checking

The TP sensor -G79- and Sender -2- for accelerator pedal position -G185- are located at the accelerator pedal and each relays the driver input separately to the engine control module. Both senders are accommodated in a joint housing.

Work sequence
- Connect vehicle diagnostic, testing and information system VAS 5051 and select vehicle system "01 - Engine electronics" from list. Ignition must be on. Connecting VAS 5051 Scan Tool

Indicated on VAS 5051:







- From list -1- select diagnostic function "08 - Reading measured value block".

Indicated on VAS 5051:







1 Enter display group
- Use keypad -2- to enter "062" for "Display group number 062" and confirm by touching Q key.

Indicated on VAS 5051:







- Check display in zones -3- and -4-.

Display Group 062:

NOTE: The engine control module converts the angle sensor voltage values into percentages referenced to 5 V and displays the percentage values (5 V supply voltage corresponds to 100 %).

- Observe display zones 3 and 4.
- Slowly floor accelerator pedal.

Percentage value displayed in zone 3 must increase steadily. Tolerance range 12...97 % is not fully utilized.

Percentage value displayed in zone 4 must likewise increase steadily. Tolerance range 4...49 % is not fully utilized.

NOTE: The value displayed in zone 3 must always be roughly twice that in display zone 4.

- Terminate function "08 - Reading measured value block" by touching <- key.

If displays are not as described:
- Check power supply and wiring of accelerator pedal position senders.

Checking power supply of accelerator pedal position senders

- Remove driver's storage compartment:
- Disconnect accelerator pedal position sender connector.
- Switch on ignition.







- Connect multimeter for voltage measurement as follows:

Connector Specification
Contact
1 + Ground approx. 5 V
1 + 5 approx. 5 V
2 + Ground approx. 5 V
2 + 3 approx. 5 V

If readings match specifications:
- Additionally check signal wires.

If readings do not match specifications:

Checking wiring
- Connect test box V.A.G 1598/31 at wiring harness to engine control module. Actual engine control module is not to be connected. Connecting VAS 5051 Scan Tool







- Check for open circuit and short to Ground/positive in following wiring.

Connector Test box V.A.G 1598/31
Contact Socket
1 72
2 73
3 36
4 35
5 33
6 34

- Eliminate open circuit in wiring/short circuit if necessary.

If no fault is found in wiring:
- Replace accelerator pedal position senders.