Accelerator Position Sensor, Checking

Accelerator Position Sensor, Checking

Special tools, testers and auxiliary items required

• (VAG1526A)

• (VAG1594A)

• (VAG1598/31)

• (VAS5051) with (VAS5051/1)

Both Throttle Position (TP) sensor (G79) and Sender -2- for accelerator pedal position (G185) are located on the accelerator pedal and completely independently signal the driver's requirements to the engine control module. Both sensors are located in one housing.

Test sequence

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

Display on (VAS5051):





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

Display on (VAS5051):





1. Enter display group

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

Display on (VAS5051):





- Check specified values for electronic throttle potentiometer voltages in display zones - 3 - and - 4 -.





• The engine control module 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 zones 3 and 4.

- Slowly depress accelerator pedal.

Percentage displayed in zone 3 should rise evenly. Tolerance range from 12 to 97% is not fully utilized.

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

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

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

If the displays are not as described:

- Check voltage supply and wiring for accelerator position sensor.

If the displays are not as described:

Checking voltage supply for accelerator position sensors

- Remove driver's storage compartment.

- Disconnect connector for accelerator 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:

Checking wiring

- Connect test box (VAG1598/31) to wiring harness for engine control module; do not connect engine control module. Refer to => [ Wiring and Component Check with Test Box VAG 1598/31 ] Wiring and Component Check With Test Box VAG 1598/31.

- Check for open circuit and short to positive or Ground in following wiring connection:









- Repair any open/short circuit as necessary.

If no wiring malfunction is detected:

- Replace accelerator position sensors.