Indicator and Warning Lamps

AUTOMATIC TRANSMISSION
The transmission control module (TCM) activates the combined instrument panel warning lamp. The lamp lights when the ignition is turned on and when driving if:

- The gear selector is in positions-3 or L
- Driving mode W (winter) has been selected.

The lamp flashes when the ignition is turned on and when driving if:

- The TCM has detected a fault in the transmission.

If the fault is intermittent the indicator and warning lamp will go out after the ignition has been turned on and off a certain number of times. The ignition may have to be switched on up to five times, depending on the diagnostic trouble code (DTC) that has been stored. For DTC AT-235, High oil temperature, the lamp flashes only as long as the temperature of the oil exceeds +140°C.





MALFUNCTION INDICATOR LAMP (MIL)
The MIL lamp is activated if the engine management systems malfunction. These malfunctions can cause engine running problems and result in the engine failing to maintain required emission levels. In some markets where an on-board diagnostics system OBD II is a statutory requirement, the TCM can also activate the malfunction indicator lamp (MIL). The TCM sends a request to the engine control module (ECM) to activate the MIL if a transmission malfunction that affects exhaust emissions occurs. (ECM Motronic 4.4 posts a DTC when the transmission sends a request for the MIL.) The MIL lights when the system posts the following automatic transmission DTCs:

AT-121 Shift solenoid S1, short-circuit to ground
AT-122 Shift solenoid S1, fault on the solenoid circuit
AT-123 System pressure solenoid STH, short-circuit to supply
AT-132 Control module, STH driver stage short-circuit
AT-213 Throttle position (TP) sensor signal, signal too high
AT-221 Shift solenoid S2, short-circuit to ground
AT-222 Shift solenoid S2, fault in the solenoid circuit
AT-223 Throttle position (TP) sensor signal, signal too low
AT-232 Vehicle speed signal VSS, no signal
AT-311 Transmission speed sensor, no signal
AT-313 Gear selector sensor, incorrect signal
AT-321 Gear 1, incorrect ratio
AT-322 Gear 2, incorrect ratio
AT-323 Gear 3, incorrect ratio
AT-324 Gear 4, incorrect ratio