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

Instrumentation, Message Center and Warning Chimes

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

Normal Operation

The Instrument Cluster (IC) receives the Malfunction Indicator Lamp (MIL) data from the PCM over the High Speed Controller Area Network (HS-CAN) communication bus. If an emissions concern exists, the PCM sets a DTC and sends a message to the IC (Instrument Cluster) to illuminate the MIL (Malfunction Indicator Lamp). If a mis-fire condition exists, the PCM sets a DTC and sends the IC (Instrument Cluster) a message to flash the MIL (Malfunction Indicator Lamp). If the MIL (Malfunction Indicator Lamp) message is missing or if the data is deemed invalid by the IC (Instrument Cluster) for greater than 5 seconds, the IC (Instrument Cluster) sets DTC U0100 and defaults the MIL (Malfunction Indicator Lamp) on.

NOTE: If DTC U0100 is set in the IC (Instrument Cluster) other symptoms may also be present such as an inoperative speedometer, tachometer or temperature gauge.

This pinpoint test is intended to diagnose the following:

- PCM

- IC (Instrument Cluster)

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

S1 RETRIEVE THE RECORDED DTCs FROM THE IC (Instrument Cluster) SELF-TEST

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

Is DTC U0100 recorded?

Yes
GO to Pinpoint Test AT. Pinpoint Test AT: DTC U0100

No
GO to S2.

S2 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
REFER to Computers and Control Systems Information.

No
GO to S3.

S3 CARRY OUT THE IC (Instrument Cluster) INDICATOR LAMP 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 on and off. Observe the MIL (Malfunction Indicator Lamp).

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

Yes
INSTALL a new PCM. TEST the system for normal operation.

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