MIL Circuit: Description

The IG2 relay energized by the power source control ECU applies the battery voltage to the malfunction indicator lamp (MIL) in the combination meter while the main system is ON.

When it is necessary, the ECM grounds the W terminal line and illuminates the MIL.

In order to perform functional check visually, the MIL is illuminated when the power switch is first turned ON(IG).

If the MIL is ON or OFF all of the time, use the procedure below to troubleshoot it. The MIL is used to indicate a vehicle malfunction which was detected by the ECM. Follow this procedure using Techstream or the OBD II scan tool to determine the cause of the problem and to check the MIL.