Throttle valve potentiometer -G69-
On a petrol engine the potentiometer is a component part of the throttle valve control part -J338-. It can be found on the throttle valve housing (engine).
On a Diesel engine the "Throttle valve signal" is generated in the sender for accelerator pedal position -G79-. The sender can be found near the accelerator pedal.
The throttle valve potentiometer is one of the engine control unit sensors. However the gearbox control unit also requires the throttle valve potentiometer signal.
For this reason the signal from the engine control unit is transmitted to the automatic gearbox control unit.
On vehicles with Data bus the automatic gearbox control unit receives the throttle valve potentiometer signal from the Data bus.
On vehicles without Data bus the signal is made available via a wire from the engine control unit.
The self-diagnosis of the automatic gearbox only checks the signal, not the potentiometer! On vehicles without Data bus the wire for the signal is also checked.
The signal can only be read-out in measured value block.
=> Read measured value block
; Display group number 001 and 003
It is therefore imperative that the self-diagnosis of the engine control unit is also carried out when the self-diagnosis indicates that the throttle valve potentiometer is faulty.
Checking and adjusting or removing and installing throttle valve potentiometer
=> Repair group 24; depending on engine code
=> Repair group 20