Throttle Position (TP) Sensor, Checking

Throttle Position (TP) Sensor, Checking







Special tools and equipment
- VAG1526A or Fluke 83 Multimeter
- VAG1594A Voltage tester
- VAG1598/31 Test box
- VAS5051 Vehicle diagnosis, testing and information system with VAS5051/1 Adapter

The Throttle Position (TP) sensors (Throttle Position 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 independent of each other. Both sensors are stored in one housing.

Work sequence
- Connect VAS5051 tester, Vehicle Diagnostic, Testing and Information System VAS 5051, Connecting and Selecting Functions and select vehicle system "01 - Engine electronics". Ignition must be switched on.







Display on VAS5051:
- Select diagnostic function "08 - read measured value block" in selection -1-.







Display on VAS5051:
1 - Enter display group. Max. input value = 255
- Select function "062" in button field -2- for "display group number 062" and press Q button to confirm input.







Display on VAS5051:
- Check specified values for TP sensor voltages in display fields 3 and 4.







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

Percent indication in display field 3 must rise uniformly. Tolerance range 12 to 97% is not completely utilized.

Percent indication in display field 4 must also rise uniformly. 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.

- Press <- button to end function "08 - Read measuring value block".

If indications do not resemble description:
- Check voltage supply and wiring connections of accelerator pedal (throttle) position sensor.

Checking voltage supply of Throttle Position (TP) sensor

- Remove driver's side storage compartment.
- Disconnect harness connector for throttle 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 wiring connections from Engine Control Module (ECM) to throttle position sensor.

Checking wiring connections
- Connect VAG1598/31 test box at wiring harness to Engine Control Module (ECM) but do not connect ECM. Scan Tool Testing and Procedures







- Check following wiring 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 in wiring or short circuit if necessary.

If no malfunctions are found in wires:
- Replace Throttle Position (TP) sensor.