Pinpoint Test K: The Engine Over-Temperature Warning Indicator Is Never/Always On

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

Pinpoint Test K: The Engine Over-Temperature Warning Indicator Is Never/Always On

Normal Operation

The engine over-temperature warning indicator informs the driver that the engine coolant is overheating due to loss of engine coolant fluid or other cause, and that the PCM is in failsafe cooling mode. There are 2 levels of failsafe cooling mode. The first mode is when the PCM provides engine operation but takes on the limp home strategy. The second mode is when the PCM determines that the engine is sufficiently over-temperature and is about to be shut down by the PCM. In both modes, the PCM provides the engine over-temperature information to the Instrument Cluster (IC) to illuminate the engine over-temperature warning indicator.

This pinpoint test is intended to diagnose the following:

- PCM
- IC



PINPOINT TEST K: THE ENGINE OVER-TEMPERATURE WARNING INDICATOR IS NEVER/ALWAYS ON

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K1 RETRIEVE THE RECORDED DTCs FROM THE CONTINUOUS AND ON-DEMAND PCM SELF-TESTS


- Check for recorded PCM DTCs from the continuous and on-demand self-tests.
- Are any DTCs recorded?

Yes
REFER to Computers and Control Systems Information.

No
GO to K2.

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K2 CARRY OUT THE IC INDICATOR LAMP CONTROL ACTIVE COMMAND USING THE SCAN TOOL


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IC DataLogger.
- Select the IC failsafe warning indicator (OVTEMP_LMP) active command on and off while monitoring the engine over-temperature warning indicator.
- Does the engine over-temperature warning indicator illuminate when commanded on, and turn off when commanded off?

Yes
GO to K3.

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

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K3 CHECK FOR CORRECT PCM OPERATION


- Disconnect all the PCM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the PCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

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

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

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