Fault Display

Fault Display









The E34 fault indicator is provided by the check control system through the instrument cluster matrix display. The check control module is responsible for signaling the cluster matrix to post the warning when the TCM has recognized a fault.

The check control module produces a voltage that is pulsed (low) by the TCM during normal operation. With a fault detected by the self-diagnostic feature of the control module, a fault report is signalled to the check control module by a constant high voltage level. The report is delivered to the instrument cluster which activates the "TRANS PROGRAM" display.

The integrity of the signal/wire is monitored by the check control module by the presence of the pulsed high/low signal.

The E36 version utilizes an indicator lamp for transmission operating status. The operation of the lamp is as follows:
- Ignition switched on - lamp on (self-check)
- Engine running/driving - lamp off - system OK
- Engine running/driving - lamp on - fail-safe (fault)

The instrument cluster produces a voltage that is pulsed (low) by the EGS control unit module during normal operation. If a fault is detected by the self-diagnostics of the control module, a fault report is signalled to the instrument cluster by a constant high voltage level, which illuminates the indicator bulb.

The integrity of the signal/wire is monitored by the cluster by the presence of the pulsed signal.