Angle Sensors For Throttle Drive -G187- and -G188-, Checking

Angle Sensor 1 For Throttle Drive -G187- And Angle Sensor 2 For Throttle Drive - G188-, Checking

Angle sensor 1 for throttle drive -G187- and Angle sensor 2 for throttle drive -G188- provide the engine control module with information on the position of the throttle valve. Both angle sensors are located in the throttle valve control module.

Work sequence

- Connect vehicle diagnostic, testing and information system VAS 5051 and select vehicle system "01 - Engine electronics" from list. Ignition must be on. Connecting VAS 5051 Scan Tool

Indicated on VAS 5051:







- From list -1- select diagnostic function "08 - Reading measured value block".

Indicated on VAS 5051:







1 Enter display group
- Use keypad -2- to enter "062" for "Display group number 062" and confirm by touching Q key.

Indicated on VAS 5051:







- Check display in zones -1- and -2-.

NOTE: The engine control module converts the angle sensor voltage values into percentages referenced to 5 V and displays the percentage values (5 V supply voltage corresponds to 100 %).

- Observe display zones 1 and 2.
- Slowly press accelerator pedal to floor.

Percentage value displayed in zone 1 must increase steadily. Tolerance range 3...93 % is not fully utilized.

Percentage value displayed in zone 2 must decrease steadily. Tolerance range 97...3 % is not fully utilized.

Display Group 062:

NOTE:
- The reason for the display in zone 1 increasing, whereas the display in zone 2 decreases, is that the potentiometers (angle sensors) in the throttle valve control module operate in opposite directions.
- In other words, the voltage tap value of angle sensor 1 moves towards 5 V (the further the throttle valve is opened, the greater the voltage becomes; the percentage reading increases).
- The voltage tap value of angle sensor 2 moves away from 5 V towards 0 V (the further the throttle valve is opened, the lower the voltage becomes; the percentage reading decreases).
- Terminate function "08 - Reading measured value block" by touching key.

If displays are not as described:
- Check power supply and wiring of throttle valve control module. Pay particular attention to the possibility of connectors being disconnected or corroded.
- Check accelerator pedal position senders. Testing and Inspection

Checking power supply of throttle valve control module

- Disconnect connector of throttle valve control module.
- Switch on ignition.







- Connect multimeter for voltage measurement as follows:

Connector Specification
Contact
2 + Ground approx. 5 V
2 + 6 approx. 5 V

If readings do not match specifications:







Checking wiring
- Disconnect connector of throttle valve control module.
- Connect test box V.A.G 1598/31 at wiring harness to engine control module. Actual engine control module is not to be connected. Wiring And Component Check Using Test Box V.A.G 1598/31
- Check for open circuit and short to Ground/positive in following wiring:

Connector Test box V.A.G 1598/31
Contact Socket
1 92
2 83
3 117
4 84
5 118
6 91

- Eliminate open circuit in wiring/short circuit if necessary.

If no fault is found in wiring:
- Replace throttle valve control module.