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

Instrumentation, Message Center and Warning Chimes

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

Normal Operation

The Malfunction Indicator Lamp (MIL) is controlled by the Instrument Cluster (IC) 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 more than 5 seconds, the IC (Instrument Cluster) sets DTC U0100 in continuous memory and defaults the MIL (Malfunction Indicator Lamp) on.

NOTE: If DTC U0100 is set in the IC (Instrument Cluster), other observable symptoms may be an inoperative speedometer, tachometer or odometer.

This pinpoint test is intended to diagnose the following:

- PCM

- IC (Instrument Cluster)

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

T1 CARRY OUT THE IC (Instrument Cluster) WARNING LAMPS AND CHIME ACTIVE COMMAND USING THE SCAN TOOL

- Ignition ON.

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

- Select the IC (Instrument Cluster) MIL (Malfunction Indicator Lamp) (MIL_IC) 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 commanded on and turn off when commanded off?

Yes
GO to T2.

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

T2 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 PCM DTCs recorded?

Yes
REFER to Computers and Control Systems Information.

No
GO to T3.

T3 RETRIEVE THE RECORDED DTCs FROM THE IC (Instrument Cluster) SELF-TEST

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

Are any DTCs recorded?

Yes
For DTC U0100, GO to Pinpoint Test AV Pinpoint Test AV: DTC U0100.

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.