Pinpoint Test Aa: The Mil (Malfunction Indicator Lamp) Is Never Or Always On
- Normal Operation and Fault Conditions
See MIL. REFER to: Instrument Panel Cluster (IPC) - System Operation and Component Description .
If the MIL request message is missing or invalid for less than 5 seconds, the IPC defaults the MIL to its last state (on or off) based upon the last known message received.
If the MIL request message is missing for 5 seconds or longer, the MIL on.
Possible Sources
- Communication concern
- PCM concern
- GWM concern
- IPC
- AA1 RETRIEVE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCS) FROM THE IPC (INSTRUMENT PANEL CLUSTER) SELF-TEST
- Ignition ON.
- Using a diagnostic scan tool, perform the IPC self-test.
Are any Diagnostic Trouble Codes (DTCs) recorded?
Yes REFER to DTC Chart: IPC in Diagnostic Trouble Code (DTC) Chart . No GO to AA2 - AA2 PERFORM THE PCM (POWERTRAIN CONTROL MODULE) KOEO (KEY ON, ENGINE OFF) SELF-TEST
- Using a diagnostic scan tool, perform the PCM KOEO self-test.
Are any Diagnostic Trouble Codes (DTCs) recorded?
Yes REFER to the appropriate Electronic Engine Controls article. No GO to AA3 - AA3 CHECK THE GWM (GATEWAY MODULE A) DIAGNOSTIC TROUBLE CODES (DTCS)
- Using a diagnostic scan tool, check the GWM Continuous Memory Diagnostic Trouble Codes (CMDTCs).
Are any Diagnostic Trouble Codes (DTCs) recorded?
Yes REFER to: Communications Network . No GO to AA4 - AA4 CARRY OUT THE IPC (INSTRUMENT PANEL CLUSTER) INDICATOR LAMP CONTROL ACTIVE COMMAND USING A DIAGNOSTIC SCAN TOOL
- Using a diagnostic scan tool, view the IPC Parameter Identifications (PIDs).
- Access the IPC and control the MIL PID
- Command the MIL on and off while observing the indicator.
Does the MIL illuminate when commanded on and turn off when commanded off?
Yes If the MIL is never on, the system is operating correctly. If the MIL is always on, GO to AA5 No Install a new IPC. Refer to Instrument Panel Cluster (IPC) . - AA5 CHECK FOR CORRECT PCM (POWERTRAIN CONTROL MODULE) OPERATION
- Ignition OFF.
- Disconnect and inspect all PCM connectors.
- Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
- Reconnect the PCM connectors. Make sure they seat and latch correctly.
- Operate the system and determine if the concern is still present
Is the concern still present?
Yes CHECK OASIS for any applicable service articles: TSB, GSB, SSM or FSA. If a service article exists for this concern, DISCONTINUE this test and FOLLOW the service article instructions. If no service articles address this concern, Refer to PCM GUIDED ROUTINE TESTING No The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.