Pinpoint Test P: The Malfunction Indicator Lamp (MIL) Is Never/Always On

Instrumentation, Message Center and Warning Chimes

Pinpoint Test P: The Malfunction Indicator Lamp (MIL) Is Never/Always On

Normal Operation

The Malfunction Indicator Lamp (MIL) is controlled by the Instrument Panel Cluster (IPC) using data sent from the PCM over the High Speed Controller Area Network (HS-CAN) communication bus.

If the MIL (Malfunction Indicator Lamp) status message is missing or invalid for less than 5 seconds, the MIL (Malfunction Indicator Lamp) remains in the last indication mode (on or off) based upon the last known good data message. If the MIL (Malfunction Indicator Lamp) status message is missing for more than 5 seconds, the IPC (Instrument Panel Cluster) sets DTC U0100:00 in continuous memory and defaults the MIL (Malfunction Indicator Lamp) on. If the MIL (Malfunction Indicator Lamp) status message is deemed invalid for more than 5 seconds, the IPC (Instrument Panel Cluster) defaults the MIL (Malfunction Indicator Lamp) on.

NOTE: If DTC U0100:00 sets in the IPC (Instrument Panel Cluster), other observable symptoms may be an inoperative speedometer, tachometer or odometer.

This pinpoint test is intended to diagnose the following:

- PCM

- IPC (Instrument Panel Cluster)

PINPOINT TEST P : THE MIL (Malfunction Indicator Lamp) IS NEVER/ALWAYS ON

P1 CARRY OUT THE IPC (Instrument Panel Cluster) MIL (Malfunction Indicator Lamp) ACTIVE COMMAND USING THE SCAN TOOL

- Ignition ON.

- Enter the following diagnostic mode on the scan tool: IPC (Instrument Panel Cluster) DataLogger.

- Select the IPC (Instrument Panel Cluster) MIL (Malfunction Indicator Lamp) (MIL) active command. Command the MIL (Malfunction Indicator Lamp) on and off. Observe the MIL (Malfunction Indicator Lamp).

Does the MIL (Malfunction Indicator Lamp) illuminate when selected on and turn off when selected off?

Yes
GO to P2.

No
INSTALL a new IPC (Instrument Panel Cluster). REFER to Instrument Panel Cluster (IPC) Service and Repair. TEST the system for normal operation.

P2 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO (Key ON Engine OFF) SELF-TEST

- Check the recorded PCM DTCs from the Key ON Engine OFF (KOEO) self-test.

Are any PCM DTCs recorded?

Yes
REFER to Computers and Control Systems Information.

No
GO to P3.

P3 RETRIEVE THE RECORDED DTCs FROM THE IPC (Instrument Panel Cluster) SELF-TEST

- Check for recorded IPC (Instrument Panel Cluster) DTCs from the self-test.

Is DTC U0100:00 recorded?

Yes
GO to Pinpoint Test AM Pinpoint Test AM: DTC U0100:00 and P1607:87.

No
If the MIL (Malfunction Indicator Lamp) is never on, the system is operating correctly at this time.

If the MIL (Malfunction Indicator Lamp) is always on, INSTALL a new PCM. TEST the system for normal operation.