Code 12 (Pedal Position Sensor)

PEDAL POSITION SENSOR POTENTIOMETER
Explanation
This defect code is stored when the control unit detects opening or closing of the Pedal Value Sender (PWG) switch and this does not comply with the calculated PWG angle or the PWG angle is outside the valid angle range (approx. -5° to approx. 87°).

Effect: When defect code is set (Electronic Throttle Control (EML) warning lamp "ON"): Power reduction by limited EML Throttle Valve (DK) opening angle and reduced throttle (DK) opening speed will occur.

NOTE: Take particular care when checking the PWG potentiometer (status monitoring) to ensure that the PWG switch is "ON" at approx. >9° PWG potentiometer value.

Troubleshooting
- Check PWG switch and PWG potentiometer (status monitoring)
- Check voltage supply for PWG potentiometer, PWG switch and kick-down switch (approx. 5 V ) from the EML control unit to the pedal position sensor at the pedal position sensor.
- Check wires from the EML control unit to the pedal position sensor.
- Check PWG switch and PWG potentiometer for continuity (potentiometer test with oscilloscope).
- Proceed with other displayed scan tool diagnostic instructions where applicable.