Malfunction Indicator Lamp (MIL), Significance

Malfunction Indicator Lamp (MIL) Function, Checking
If emissions malfunctions are recognized by the TCM, the Malfunction Indicator Lamp (MIL) will be switched on.







Location of the MIL: integrated in speedometer in instrument cluster


NOTE: When the MIL is switched on, it will either blink or light continuously The DTC memory for the TCM must be checked.
- MIL flashing: there is a malfunction that could damage the Three Way Catalytic Converter (TWC). In this case, drive only with reduced power.
- MIL continuously on: there is a malfunction that degrades emissions. Check DTC memory of the Engine Control Module (ECM) or the TCM.
- If there are driveability problems (e.g. a customer complaint) and the MIL is not on, perform the MIL functional because malfunctions can be stored that do not switch the MIL on.


MIL functional check
- Switch ignition on: MIL must come on.

If the MIL does not come on when the ignition is switched on (with the engine not running):
Check DTC memory. If necessary, check wiring per wiring diagram or replace light bulb.

- Start engine and let idle: MIL must switch off after several seconds.

If the MIL does not switch off after the engine is started: Check DTC memory.