With Manufacturer's Scan Tool
Accelerator Pedal Position Sensor, Checking
Special tools and equipment
- V.A.G 1526 A Hand multimeter
- V.A.G 1594 A Adapter set
- V.A.G 1598/31 Test box
- VAG 1551 scan tool or vehicle system tester V.A.G 1552 with cable V.A.G 1551/
- Wiring diagram
Function
Both the Throttle Position (TP) sensor -G79 and the Accelerator pedal position sensor 2 -G185- on the accelerator pedal pass the driver's requirements on to the engine control module independently of one another. Both senders are installed together in a housing.
Check conditions
- The fuses must be OK.
- The battery voltage must be at least 11.5 V.
Test sequence
- Connect VAG 1551 scan tool (V.A.G 1552) and with ignition switched on select engine electronics control module with "Address word" 01:
Indicated on display
Rapid data transfer HELP
Select function XX
- Press keys 0 and 8 for the function "Read measured value block" and confirm entry with Q key.
Indicated on display
Read measured value block
Input display group number XXX
- Press keys 0, 6 and 2 for the "Display group number 62" and confirm entry with Q key.
Indicated on display: (1 to 4 = Display zones)
Read measured value block 62 ->
1 2 3 4
- Check specification of TP sensor -G79- at idling stop in display zone 3.
Specification: 6 to 96%
NOTE: The engine control module calculates the voltage values of the angle sensor in percent relative to 5 Volt and displays these as a percentage figure (5 Volt supply voltage equates to 100%).
- Operate accelerator pedal slowly until fully depressed and observe angle sender figures in display zones 3 and 4:
- Percent figures in display zone 3 must rise evenly. Tolerance range of 6 to 96% is not covered completely.
- Percent figures in display zone 4 must rise evenly. Tolerance range of 3 to 48% is not covered completely.
NOTE: The figure displayed in display zone 3 must always be approximately double that displayed in display zone 4.
- Press -> key.
- Press keys 0 and 6 for function "End output" and confirm entry with Q key.
- Switch ignition off.
If the display does not indicate as described:
- Check accelerator pedal position sensor voltage supply and wiring connections.
Checking voltage supply and wiring to control module
- Remove driver's stowage compartment:
- Pull 6-pin connector off TP sensor / accelerator pedal position sensor.
- Switch ignition on.
- Connect multimeter to measure voltage at following contacts of connector using adapter cables from V.A.G 1594 A
Contact 1 + Ground
Contact 1 + 5
Contact 2 + Ground
Contact 2 + 3
Specification: minimum 4.5 V
- Switch ignition off.
If no voltage is present:
- Connect test box V.A.G 1598/31 to control module wiring harness. Engine control module remains disconnected.
- Check wiring between test box and connector for open circuit according to wiring diagram.
Contact 1 + socket 72
Contact 2 + socket 73
Contact 3 + socket 36
Contact 4 + socket 35
Contact 5 + socket 33
Contact 6 + socket 34
Wire resistance: max. 1.5 Ohms
- Additionally check wiring for short to battery positive or Ground.
- Additionally check wires for short to one another.
If no malfunction is detected in the wiring:
- Replace TP sensor / accelerator pedal position sender.
Vehicles with automatic transmission
- Adapt control module for automatic transmission:
Continued for all vehicles
- Check DTC memory.
- Read readiness code.
- Generate readiness code again if DTC memory has been erased or engine control module separated from permanent positive.