Malfunction Indicator Lamp (MIL) Significance

Malfunction Indicator Lamp (MIL) -K83- In Instrument Cluster
If the engine control module (ECM) detects malfunctions which result in deterioration of exhaust emissions, these malfunctions will be indicated by illumination of exhaust gas warning lamp.

After switching on the ignition the ECM switches on the Malfunction Indicator Lamp (MIL) -K83-. Shortly after starting the engine, the MIL goes out if the ECM does not detect a malfunction through a deterioration of the exhaust emissions, and if the ECM activation of the lamp is ok.

If DTCs which cause the exhaust emission to deteriorate are detected when operating the engine, the ECM switches on the MIL. (These DTCs are listed in the DTC table). At the same time, an entry is made in the ECM DTC memory.

When switched on, the MIL may flash or illuminate constantly. In any case the DTC memory must be checked. Reading Diagnostic Trouble Codes

Continuous illumination:
A malfunction is present which causes deterioration of the exhaust emission. Check DTC memory for ECM or automatic transmission (if available).

If there is a drive problem or a customer concern and the MIL is not illuminated the DTC memory must be checked. DTCs which do not switch on the MIL immediately, but only after recognizing the malfunction after restarting the engine, can also be stored.

Flashing:
A malfunction is present which under these driving conditions will cause damage to the Three Way Catalytic Converter (TWC) (e.g. misfiring). In this case driving may only continue at reduced power.

Malfunction Indicator Lamp (MIL) -K83- in instrument cluster, checking

Functional check on MIL
- Switch ignition on.
- The Malfunction Indicator Lamp (MIL) -K83- for self-diagnosis must illuminate.

- Start engine.
- Shortly after starting the engine the MIL goes out if no exhaust emission related DTC is stored in the DTC memory.


NOTE: The switch-on signal for the MIL is transferred via CAN-bus to the instrument cluster by the ECM. Check the data exchange between ECM and other CAN-bus control modules.