Table A1-2 Malfunction Indicator Lamp (MIL) on Steady

Malfunction Indicator Lamp (MIL) "ON" Steady:

Partial PCM Wiring Schematic:

Circuit Description

There should be a steady Malfunction Indicator Lamp (MIL) when the ignition is "ON," prior to starting the engine. Battery ignition voltage is supplied to the MIL. The PCM will turn the MIL "ON" by grounding the control circuit at the PCM. A steady MIL with the engine running suggests a short to ground in the MIL control circuit, or a DTC is stored.


Diagnostic Aids

An intermittent malfunction, may be caused by a poor connection, rubbed through wire insulation, or a wire broken inside the insulation. Inspect harness connectors for backed out terminals, improper mating, broken locks improperly formed or damaged terminals and poor terminal-to-wire connections before component replacement.

^ Check for a shorted MIL control circuit between the PCM and the I/P Cluster Assembly.

^ A shorted I/P Cluster Assembly board may cause the MIL to stay on.


Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

1. The Powertrain OBD System Check prompts the technician to complete some basic checks and store the freeze frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

2. Checks for a short to ground in MIL control circuit.