Accelerator Position Sensor, Checking

Accelerator Position Sensor, Checking







Special tools and equipment

- VAG 1526 A
- VAG 1594 A
- VAG 1598/31
- VAS 5051 with VAS 5051/1

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 VAS 5051 and select vehicle system "01 - Engine electronics" in selection. Ignition must be switched on. Connecting VAS 5051 Scan Tool

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 zone -2- and confirm entry by pressing -Q- button.

Display on VAS 5051:







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

Display Group 062:

- 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 <- 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 VAG 1598/31 to wiring harness for engine control module; do not connect engine control module. Wiring and Component Testing Using VAG1598/31 Test Box

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







Connector Test box VAG 1598/31
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.