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

Instrumentation, Message Center and Warning Chimes

Pinpoint Test V: 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).

If the MIL (Malfunction Indicator Lamp) status message is missing or invalid for less than 5 seconds, the IPC (Instrument Panel Cluster) defaults the MIL (Malfunction Indicator Lamp) to its last state (on or off) based upon the last known good message received. 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.

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 V : THE MIL (Malfunction Indicator Lamp) IS NEVER/ALWAYS ON

V1 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) active command (MIL). 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 V2.
No
INSTALL a new IPC (Instrument Panel Cluster). REFER to Instrument Panel Cluster (IPC) . TEST the system for normal operation.

V2 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO (Key ON Engine OFF) SELF-TEST

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

Are any PCM DTCs recorded?

Yes
REFER to Computers and Control Systems. TEST the system for normal operation.
No
GO to V3.

V3 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 AT. Pinpoint Test AT: DTC U0100:00
No
If the MIL (Malfunction Indicator Lamp) is never on with the KOEO (Key ON Engine OFF), 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.