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 VAG1551/3A

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 control module for engine electronics using "address word" 01. Ignition must remain switched on. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks" Testing and Inspection

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
Enter 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.

Display Group 062:

- 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 Specified value
Terminal
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 Engine Control Module (ECM), do not connect ECM. Refer to "Scan Tool Testing/Wiring and Component Testing Using VAG1598/31 Test Box", Testing and Inspection






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

Harness connector VAG1598/31 test box
Terminal 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.