Malfunction Indicator Lamp (MIL) Significance

Malfunction Indicator Lamp (MIL), Function
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.

Location of MIL







NOTE:
When a recognized malfunction switches on the MIL, it will either blink or light continuously. In either case, DTC memory for the ECM and the TCM 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 until the MIL goes out or stays on continuously. 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 for the ECM and the TCM 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 for the ECM and TCM must be checked, as there may be malfunctions stored that do not switch the MIL on immediately.


Functional testing
- Switch ignition on.

The MIL must light up

If the MIL does not light:
- Check DTC memory.
- Check wiring to MIL using appropriate wiring diagram.