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

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

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

Normal Operation

The Malfunction Indicator Lamp (MIL) informs the driver of a malfunction in the powertrain that affects the vehicle emissions system. When an emission related fault condition exists, the PCM sets a DTC and sends a command to the Instrument Cluster (IC) over the High Speed Controller Area Network (HS-CAN) to turn on the MIL.

This pinpoint test is intended to diagnose the following:

- PCM
- IC



PINPOINT TEST O: THE MIL IS NEVER/ALWAYS ON

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O1 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO SELF-TEST


- Retrieve the 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 O2.

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O2 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST


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

Yes
For DTC U1900, REFER to Information Bus.

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

No
GO to O3.

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O3 CARRY OUT THE IC INDICATOR LAMP ACTIVE COMMAND USING THE SCAN TOOL


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IC DataLogger.
- Select the IC MIL indicator (MIL_IC) active command. Command the MIL on and off. Observe the MIL.
- Does the MIL illuminate when commanded on, and turn off when commanded off?

Yes
INSTALL a new PCM. REFER to Computers and Control Systems. TEST the system for normal operation.

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

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