Pinpoint Test C: The Temperature Gauge Is Inoperative

Instrumentation and Warning Chimes

Pinpoint Tests

Pinpoint Test C: The Temperature Gauge Is Inoperative

Normal Operation

The PCM receives the Engine Coolant Temperature (ECT) status from the ECT sensor through hardwired circuitry. The PCM transmits the engine temperature status to the Instrument Cluster (IC) over the High Speed Controller Area Network (HS-CAN) communication bus. The IC monitors the ECT data received from the PCM and commands the engine temperature gauge to a corresponding position. The IC sets DTC U0100 in continuous memory if the coolant temperature data message is missing from the PCM for more than 5 seconds and the engine temperature gauge fails to operate and moves the temperature gauge to C (cold).

This pinpoint test is intended to diagnose the following:

- PCM
- IC



PINPOINT TEST C: INCORRECT TEMPERATURE GAUGE INDICATION

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C1 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO SELF-TEST


- Retrieve the recorded DTCs from the PCM Key ON Engine OFF (KOEO) self-test.
- Are any DTCs retrieved?

Yes
REFER to the Computers and Control Systems Information.

No
GO to C2.

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C2 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST


- Retrieve the recorded DTCs from the IC self-test.
- Is DTC U0100 retrieved?

Yes
Go To Pinpoint Test AK. Pinpoint Tests AK: DTC U0100

No
GO to C3.

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C3 CARRY OUT THE IC GAUGES 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. Scroll the temperature gauge at 20%, 50% and 70%.
- Does the temperature gauge indicate approximately one-quarter of the gauge sweep between cold (C) and mid-range at 20%, mid-range at 50% and three-quarter of the gauge sweep between mid-range and hot (H) at 70%?

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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