Fault Display

Fault Indication with Serial Data Transfer
The transmission control unit transfers data on the fault indicator line (Pin 29) relating to the transmission oil temperature and the selector lever coding (4th or 5th gear) to the instrument cluster.

The fault lamp is activated by the instrument cluster when a voltage of 12 V is applied on this line for longer than 1 sec. This is the case when the Electronic Transmission Control (EGS) control unit is still in its initialization phase (ignition "ON", engine still not started), or in the emergency program or when the wire has a break (pull-up resistor in the instrument cluster).