Accelerator Pedal Position Sensor: Testing and Inspection

Both the Throttle Position (TP) sensor - 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.

Test sequence
- Connect VAS5051 tester or VAG 1551 scan tool and select control module for engine electronics using "address word" 01.
- Ignition must remain switched on for this.

When indicated on display:


Rapid data transfer HELP
Select function XX


- Press buttons -0- and -8- to select "Read Measuring Value Block" and press -Q- button to confirm input

When indicated on display:


Read Measuring Value Block Q
Input display group number XXX


- Press buttons -0- , -6- and -2- to select "display group number 062" and press -Q- button to confirm input.

Indicated on display:


Read Measuring Value Block 62 ->
1 2 3 4


- Check specified value for E - Gas potentiometer voltages.

Display Group 62:

NOTE: Engine Control Module (ECM) calculates the voltage values of the angle sensors in percent relative to 5 volts and displays these percentage values. (5 volts supply voltage represents 100 %).


- Observe display field 3 and 4.
- Slowly depress accelerator pedal completely.

Percent indication in display field 3 must climb uniformly. The tolerance range 12 - 97% is not used completely during this.
Percent indication in display field 4 must also climb uniformly. The tolerance range 4 - 49 % is not used completely during this.


NOTE: The indicated value in display field 3 must always be approx. twice as large as the value in display field 4.


If indications do not resemble description:
- Check voltage supply and wire connections of sensor for accelerator pedal position.







Checking voltage supply of the sensors for accelerator pedal position
- Remove driver - side storage compartment.
- Disconnect harness connector for accelerator pedal position sensor.
- Switch ignition on.
- Connect multimeter for voltage measurement as follows:

Harness connector terminal Specified value
1 + Ground approx. 5 V
1+5 approx. 5 V
2 + Ground approx. 5 V
2+3 approx. 5 V

If specified values are obtained:
- Also check signal wires.

If specified values are not obtained:
- Check wire connections from Engine Control Module (ECM) to sensors for accelerator pedal position.

Checking wire connections
- Connect VAG 1598/31 test box at wiring harness to ECM, do not connect ECM.
- Check the following wire connection for open circuit and short circuit to Ground and B+:

Harness connector terminal VAG 1598/31 test box socket
1 72
2 73
3 36
4 35
5 33
6 34

- Repair open circuit or short circuit if necessary.

If no malfunctions are found in wires:
- Replace accelerator pedal position sensor.


NOTE: For vehicles with automatic/variable transmission, the kick down function must be learned.