Malfunction Indicator Lamp Circuit Check

Circuit Description
When the Ignition Switch is initially turned to the run position, the Malfunction Indicator Lamp (MIL) will be ON steady. When the engine is running and there are no active type A or B DTCs stored, refer to Diagnostic Trouble Code (DTC) Type Definitions, the Vehicle Control Module (VCM) turns OFF the MIL. The ignition switch supplies battery voltage directly to the MIL through the gauge fuse. The VCM controls the MIL by providing a ground path through the MIL control circuit in order to turn ON the MIL.

Diagnostic Aids
An open gauge fuse will cause the entire IP cluster to be inoperative.

An intermittent may be caused by any of the following conditions:
^ A poor connection
^ Rubbed through wire insulation
^ A broken wire inside the insulation

Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Intermittents and Poor Connections Diagnosis. Symptom Related Diagnostic Procedures

Test Description
The numbers below refer to step numbers on the Diagnostic Table.
3. A MIL that responds correctly to the scan tool command indicates that the condition is not present at this time.
4. The MIL should be OFF. This step checks for a short to ground in the MIL control circuit by removing the VCM from the circuit.
6. This step checks for the MIL control circuit for a short to B+ or a problem with the VCM.
14. Locate and repair any shorts that may have caused the gauge fuse to open BEFORE replacing the fuse.