Angle Sensor for Throttle Valve Actuator, Checking

Angle Sensor for Throttle Valve Actuator, Checking

Special tools, testers and auxiliary items required

• (VAG1526A)

• (VAG1594A)

• (VAG1598/31)

• (VAS5051) with (VAS5051/1)

The Angle sensor -1- for throttle drive (power accelerator actuation) (G187) and Angle sensor -2- for throttle drive (power accelerator actuation) (G188) signal the position of the throttle valve to the engine control module. Both angle sensors are located in the throttle valve control module.

Test sequence

- Connect testing and information system (VAS5051 ) and select vehicle system "01 - Engine electronics" in selection. Refer to => [ VAS 5051, Connecting and Select Functions ] VAS 5051, Connecting and Select Functions. Ignition must be switched on.

Display on (VAS5051):





- Under - 1 - select diagnostic function "08 - Read measured value block".

Display on (VAS5051):





1. Enter display group

- Enter "062" for "display group number 062" in zone - 2 - and confirm entry by pressing Q button.

Display on (VAS5051):





- Check specified values for electronic throttle potentiometer voltages in display zones - 1 - and - 2 -.





• The engine control module converts and displays the voltage readings from the angle sensors as percentages of 5 V. (A 5 Volt supply corresponds to 100%).

- Observe readouts in display zones 1 and 2.

- Slowly depress accelerator pedal.

Percentage displayed in zone 1 should rise evenly. Tolerance range from 3 to 93% is not fully utilized.

Percentage displayed in zone 2 should fall evenly. Tolerance range from 97 to 3% is not fully utilized.

• The reason why the value in display zone 1 rises and that in zone 2 falls is that the potentiometers (angle sensors) in the throttle valve control module operate in opposite directions.

• This means that the voltage picked off by one of the angle sensors runs in the direction of 5 V. (As the throttle is opened, the voltage becomes greater and the percentage increases).

• The voltage picked off by the angle sensor 2 runs from 5 V in the direction of 0 V. (As the throttle is opened, the voltage becomes smaller and the percentage decreases).

- Exit function "08 - Read measured value block" by pressing arrow button.

If the displays are not as described:

- Check throttle valve control module voltage supply and wiring. Pay particular attention to connectors, which may be disconnected or corroded.

- Check accelerator position sensor. Refer to => [ Accelerator Position Sensor, Checking ] Accelerator Position Sensor, Checking.

Checking the voltage supply to the throttle valve control module

- Disconnect connector from throttle valve control module.

- Switch ignition on.

- Connect multimeter as follows to measure voltage:









If the specified values are not obtained:

Checking wiring

- Disconnect connector from throttle valve control module.





- Connect test box (VAG1598/31) to wiring harness for engine control module; do not connect engine control module. Refer to => [ Wiring and Component Check with Test Box VAG 1598/31 ] Wiring and Component Check With Test Box VAG 1598/31.

- Check for open circuit and short to Ground/positive or Ground in following wiring connections:





- Repair any open/short circuit as necessary.

If no wiring malfunction is detected:

- Replace throttle valve control module.