Malfunction Indicator Lamp (MIL) Significance

Malfunction Indicator Lamp (MIL) Function, Checking

If a malfunction is recognized by the Engine Control Module (ECM) or the Transmission Control Module (TCM), this is indicated by the MIL coming on.

Malfunction Indicator Lamp (MIL)







NOTE:
When a recognized malfunction switches on the MIL, it will either blink or light continuously. In either case, DTC memory must be checked.
- If the MIL starts to blink, there is a malfunction that can lead to damage of the Three Way Catalytic Converter (TWC). In this case, driving should only continue using reduced power The malfunction must be rectified as quickly as possible.
- If the MIL lights continuously, there is a malfunction that affects exhaust emissions. In this case, DTC memory must be checked, and the malfunction must be rectified as quickly as possible.
- Some malfunctions may occur without causing the MIL to come on When driveability or performance problems are reported, and there is no indication from the MIL, the operation of the MIL must be checked. In addition, DTC memory must be checked, as there may be malfunctions stored that do not switch the MIL on immediately.


Checking function
- Switch ignition on.
MIL must light up.
- If MIL does not light when ignition is switched on, check wiring to MIL as follows:







If MIL lights up when ignition is switched on, continue checking as follows:
- Start engine and let run at idle.
MIL must go out after a few seconds.

If MIL does not go out:
- Check Diagnostic Trouble Code (DTC) memory.

If there are no malfunctions stored in DTC memory: