Trouble Code 55 (Throttle Signal)

THROTTLE SIGNAL
Explanation
This defect code is stored when the Electronic Transmission Control (EGS) control unit receives no signal or a defined defect signal (duty factor 4%) from the Digital Motor Electronic (DME) control unit relating to the throttle angle. The throttle signal is pulse width-modulated and is always monitored completely by the control unit. The control unit can differentiate between the following types of defect:

- Break or short to positive
- Short to ground
- Throttle defect detected by DME control unit.

Effect of Defect
A substitute value of approx. 15% accelerator pedal position is used, i.e. the EGS control unit shifts up at a much earlier point.

Possible Cause
Wire from DME control unit to EGS control unit Pin 55 defective or wires from throttle potentiometer to DME control unit defective.