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

Instrumentation, Message Center and Warning Chimes

Pinpoint Test AE: 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 for less than 5 seconds, the MIL (Malfunction Indicator Lamp) remains in the last indication mode (on or off).

If the MIL (Malfunction Indicator Lamp) status message is missing for less than 5 seconds, the MIL (Malfunction Indicator Lamp) remains in the last indication mode (on or off). 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) message is invalid for more than 5 seconds, the IPC (Instrument Panel Cluster) defaults the MIL (Malfunction Indicator Lamp) on.

NOTE: If DTC U0100:00 is set 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 AE : THE MIL (Malfunction Indicator Lamp) IS NEVER/ALWAYS ON

AE1 CARRY OUT THE IPC (Instrument Panel Cluster) WARNING LAMPS AND CHIME 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_LAMP) active command. Command the MIL (Malfunction Indicator Lamp) on and off while observing the MIL (Malfunction Indicator Lamp).

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

Yes
GO to AE2.

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

AE2 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO (Key ON Engine OFF) SELF-TEST

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

Are any DTCs recorded?

Yes
DIAGNOSE all PCM DTCs first. REFER to Computers and Control Systems Information.

No
GO to AE3.

AE3 RETRIEVE THE RECORDED DTCs FROM THE IPC (Instrument Panel Cluster) SELF-TEST

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

Are any DTCs recorded?

Yes
For DTC U0100:00, GO to Pinpoint Test BF. Pinpoint Test BF: DTC U0100:00

For all other DTCs, REFER to DTC Charts. Instrumentation, Message Center and Warning Chimes

No
INSTALL a new PCM. TEST the system for normal operation.