Throttle Position Sensor: Testing and Inspection

Throttle Position (TP) Sensor, Checking

Special Tools and Equipment







- VAG1526A
- VAG1594A
- VAG1598/31
- VAS5051 with VAG5051/1
or
- VAG1551 with VAG1551/3B

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 VAG1551 scan tool and select the control module for engine electronics using "address word" 01. Refer to "Scan Tool Testing/Scan Tool Connecting And Initial Checks", Testing and Inspection

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 values for E-gas potentiometer voltages in display fields 3 and 4.







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 rise uniformly. The tolerance range 12 to 97% is not used completely during this.

Percent indication in display field 4 must also rise uniformly. In the process, the tolerance range of 4 to 49% is not completely utilized.


NOTE: The indicated value in display field 3 must always be about 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 Throttle Position (TP) Sensor
- 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 (GND) about 5 V
1+5 about 5 V
2+Ground (GND) about 5 V
2+3 about 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 VAG1598/31 test box at wiring harness to ECM, do not connect ECM. Refer to "Scan Tool Testing/Wire And Component Test Using VAG1598/31 Test Box", Testing and Inspection







- Check the following wire connection for open circuit and short circuit to Ground (GND) and B+:

Harness connector Terminal VAG1598/31 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 transmission, the kick down function must be learned.