Accelerator Position Sensor, Checking

Accelerator Position Sensor, Checking







Special tools and equipment
- VAG1526 A
- VAG1594 A
- 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. 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-.







NOTE: 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.

NOTE: 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 square 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:

Connector Specified value
terminal
1 + ground approx. 5 V
1 + 5 approx. 5 V
2 + ground approx. 5 V
2 + 3 approx. 5 V

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.







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

Connector Test box VAG1598/31
terminal Socket
1 72
2 73
3 36
4 35
5 33
6 34

- Repair any open/short circuit as necessary.

If no wiring malfunction is detected:
- Replace accelerator position sensors.