Malfunction Indicator Lamp (MIL) Always On

MALFUNCTION INDICATOR LAMP (MIL) ALWAYS ON

CIRCUIT DESCRIPTION
Ignition 1 voltage is supplied directly to the malfunction indicator lamp (MIL). The engine control module (ECM) turns the MIL ON by grounding the MIL control circuit. There should be a steady MIL with the ignition ON and the engine OFF.

MIL OPERATION
The MIL is located on the driver information center (DIC)/clock.

MIL FUNCTION
- The MIL informs the driver that a malfunction has occurred and the vehicle should be taken in for service as soon as possible.
- The MIL illuminates during a bulb test and a system test.
- A DTC will be stored if a MIL is requested by a diagnostic.

MIL ILLUMINATION
- The MIL will illuminate with the ignition switch ON and the engine not running.
- The MIL will turn OFF when the engine is started.
- The MIL will remain ON if the self-diagnostic system has detected a malfunction.
- The MIL may turn OFF if the malfunction is no longer present.
- If the MIL is illuminated and then the engine stalls, the MIL will remain illuminated as long as the ignition switch is ON.
- If the MIL is not illuminated and the engine stalls, the MIL will not illuminate until the ignition switch is cycled OFF, then ON.

TEST DESCRIPTION

Steps 1-2:

Steps 3-6:

The numbers below refer to the step numbers on the diagnostic table.
2. This step determines if the condition is with the MIL control circuit or the ECM.