Malfunction Indicator Lamp (MIL) Always On

Diagnostic Chart:

Schematic:

CIRCUIT DESCRIPTION
When the ignition is turned ON, the Malfunction Indicator Lamp (MIL) will momentarily flash ON then OFF and remain ON until the engine is running, if no Diagnostic Trouble Codes (DTCS) are stored. The Powertrain Control Module (PCM) controls the MIL by providing a ground path through the MIL control circuit to turn ON the MIL.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
1. The Powertrain OBD System Check prompts you to complete some of the basic checks and to store the Freeze Frame and Failure Records data on the scan tool, if applicable. This creates an electronic copy of the data that was captured when the malfunction occurred. The scan tool stores this information for later reference.
2. When the ignition switch is turned ON, the MIL should momentarily flash ON and OFF, then remain ON until the engine is running or if an emission-related DTC stores.
3. This step checks the ability of the PCM to control the MIL. The scan tool has the ability to command the MIL ON and OFF.
5. A shorted MIL circuit can be diagnosed with a scan tool.
6. For Instrument Panel Cluster (IPC) replacement procedures, refer to P Cluster Replacement in Instrument Panel, Gauges and Console.
7. Reprogram the PCM and perform the crankshaft position system variation learn procedure. Refer to the latest Techline(TM) information for PCM programming and perform the crankshaft position system variation learn procedure.