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

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

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 status message is missing for less than 5 seconds, the MIL remains in the last indication mode (on or off).

If the MIL status message is missing for less than 5 seconds, the MIL remains in the last indication mode (on or off). If the MIL status message is missing for more than 5 seconds, the IPC sets DTC U0100:00 in continuous memory and defaults the MIL on. If the MIL message is invalid for more than 5 seconds, the IPC defaults the MIL on.

NOTE: If DTC U0100:00 is set in the IPC, other observable symptoms may be an inoperative speedometer, tachometer or odometer.

This pinpoint test is intended to diagnose the following:

- PCM
- IPC



PINPOINT TEST AE: THE MIL IS NEVER/ALWAYS ON

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AE1 CARRY OUT THE IPC WARNING LAMPS AND CHIME ACTIVE COMMAND USING THE SCAN TOOL


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IPC DataLogger .
- Select the IPC MIL (MIL_LAMP) active command. Command the MIL on and off while observing the MIL.
- Does the MIL illuminate when selected on, and turn off when selected off?

Yes
GO to AE2.

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

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AE2 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO 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.

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AE3 RETRIEVE THE RECORDED DTCs FROM THE IPC SELF-TEST


- Check for recorded DTCs from the IPC self-test.
- Are any DTCs recorded?

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

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