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

Instrumentation, Message Center and Warning Chimes

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

Normal Operation

The PCM receives the engine coolant temperature status through hardwired circuitry from the Cylinder Head Temperature (CHT) sensor. The IC receives the engine coolant temperature data from the PCM over the High Speed Controller Area Network (HS-CAN). The IC monitors the engine coolant temperature data received from the PCM and when the engine coolant temperature is high, or if the vehicle has entered a failsafe cooling mode, the engine over-temperature warning indicator illuminates.

This pinpoint test is intended to diagnose the following:

- PCM
- IC



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

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Z1 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 PCM DTCs recorded?

Yes
REFER to Computers and Control Systems Information.

No
GO to Z2.

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Z2 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 all lamps (ALL_LAMP) active command on and off. Observe the engine over-temperature warning indicator.
- Does the engine over-temperature warning indicator illuminate when selected on and turn off when selected off?

Yes
INSTALL a new PCM. 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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