Throttle Position Sensor 1 and Accelerator Pedal Position Sensor 2, Checking

Throttle Position Sensor 1 and Accelerator Pedal Position Sensor 2, Checking

Special tools, testers and auxiliary items required

• Multimeter (V.A.G 1526 A)

• Connector test kit (V.A.G 1594 A)

• Test box (VAG1598/31)

• Vehicle diagnostic, testing and information system ( VAS 5051)

• Adapter (VAS 5051/1)

Both the Throttle Position (TP) sensor 1 (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.

Work sequence

- Connect vehicle diagnostic, testing and information system (VAS 5051) and select vehicle system "01 -Engine electronics" in selection. Refer to => [ VAS5051, Connecting and Selecting Functions ] VAS 5051, Connecting and Selecting Functions.

When doing this the ignition must be switched on.

Display on (VAS 5051):





- Under - 1 - select diagnostic function "08 - Read measured value block".

Display on (VAS 5051):





1. Enter display group

- Enter "062" for "display group number 062" in field - 2 - and confirm entry by pressing Q button.

Display on (VAS 5051):





- Check indication in display groups - 3 -and - 4 -.





• The ECM converts and displays the voltage readings from the angle sensors as percentages of 5 V. (A 5 Volt supply corresponds to 100%).

- Observe readouts in display fields 3 and 4.

- Slowly depress accelerator pedal.

Percentage displayed in field 3 should rise evenly. Tolerance range from 12..0.97% is not fully utilized.

Percentage displayed in field 4 should also rise evenly. Tolerance range from 4...49% is not fully utilized.

• The value displayed in field 3 must always be about twice as large as that in field 4.

- Exit function "08 - Read measured value block" by pressing arrow button.

If the displays are not as described:

- Check - 2 - for accelerator pedal position Sender (G185) voltage supply and wiring.

Voltage supply for Throttle Position (TP) sensor (G79) and Sender -2- for accelerator pedal position (G185), checking

- Remove driver's storage compartment.

- Disconnect connector for throttle position sensors.

- Switch ignition on.

- Connect multimeter as follows to measure voltage:









If specifications are obtained:

- Additionally check signal wires.

If the specified values are not obtained:

Check wiring

- Connect test box (VAG1598/31) to wiring harness for ECM; do not connect ECM. Refer to => [ Electrical Testing, with Test Box VAG 1598/31 ] Electrical Testing, With Test Box VAG 1598/31.

- Check for open circuit and short to positive (B+) or ground (GND) in following wiring connection:









- Repair any open/short circuit as necessary.

If no malfunction is found in wires:

- Replace throttle position sensor(s).