Pinpoint Test C: The Temperature Gauge Is Inoperative

Instrumentation, Message Center and Warning Chimes

Pinpoint Tests

Pinpoint Test C: The Temperature Gauge Is Inoperative

Normal Operation

The PCM receives the Engine Coolant Temperature (ECT) status through hardwired circuitry to the ECT sensor (4.0L engine), or from the Cylinder Head Temperature (CHT) sensor (4.6L engine). The Instrument Cluster (IC) receives the ECT data from the PCM over the High Speed Controller Area Network (HS-CAN). The IC monitors the engine temperature data received from the PCM and commands the temperature gauge indication with a corresponding movement of the pointer.

This pinpoint test is intended to diagnose the following:

- PCM
- IC



PINPOINT TEST C: THE TEMPERATURE GAUGE IS INOPERATIVE

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C1 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 C2.

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C2 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 C3.

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C3 CARRY OUT THE IC TEMPERATURE GAUGE ACTIVE COMMAND USING THE SCAN TOOL


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IC DataLogger.
- Select the IC temperature gauge (ENGCOOLNT) active command. Command the temperature gauge on and off. Observe the temperature gauge.
- Does the temperature gauge start at C (cold) and move to H (hot) when commanded on, and return to C (cold) 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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