Malfunction Indicator Lamp (MIL) Significance

Malfunction Indicator Lamp (MIL), Significance

If the ECM recognizes malfunctions that lead to a degradation of emissions values, it indicates them by lighting the Malfunction Indicator Lamp for exhaust.








Installation position of exhaust MIL


NOTE: The Malfunction Indicator Lamp (MIL) can blink or remain lit continuously. DTC memory should be checked in both cases.


- Blinking: There is a malfunction that causes damage to the catalytic converter in this driving condition (e.g. combustion misfire). In this case, vehicle must only be driven at reduced power!
- Continuously lit: There is a malfunction that causes increased emissions. Check DTC memory for Motronic ECM and automatic transmission (if installed).
- If there are driveability problems or if there is a customer complaint and the exhaust MIL is not lit, DTC memory must be checked. There may be DTCs stored that do not cause the exhaust MIL to light up immediately, but only if malfunction is recognized again after repeated engine starts.