Pinpoint Test D: Incorrect Temperature Gauge Indication
Instrumentation and Warning Chimes
Pinpoint Test
Pinpoint Test D: Incorrect Temperature Gauge Indication
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 concern
- IC
PINPOINT TEST D: INCORRECT TEMPERATURE GAUGE INDICATION
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D1 CHECK FOR CORRECT OPERATION OF THE COOLING SYSTEM
- Verify that the engine cooling system and thermostat are functioning correctly.
- Does the engine cooling system and thermostat operate correctly?
Yes
GO to D2.
No
REFER to Cooling System &/or Engine Block Heater.
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D2 RETRIEVE THE RECORDED DTCs FROM THE KOEO PCM SELF-TEST
- Check for recorded PCM DTCs from the Key ON Engine OFF (KOEO) self-test.
- Are any DTCs recorded?
Yes
DIAGNOSE all PCM DTCs first. REFER to Computers and Control Systems Information.
No
GO to D3.
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D3 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST
- Check for recorded DTCs from the IC self-test.
- Are any DTCs recorded?
Yes
For DTC U0100, GO to Pinpoint Test AK. Pinpoint Tests AK: DTC U0100
For all other DTCs, REFER to DTC Charts. [1][2]Diagnostic Trouble Code Descriptions
No
GO to D4.
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D4 CARRY OUT THE TEMPERATURE GAUGE ACTIVE COMMAND USING THE SCAN TOOL
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IC DataLogger.
- NOTE: Make sure to set the scan tool to 0 or full cold before beginning this step.
- Select the IC temperature gauge (ENGCOOLNT) active command. Command the temperature gauge according to the following table:
- Does the temperature gauge operate according to the above specifications?
Yes
GO to D5.
No
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.
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D5 CHECK THE COOLANT TEMPERATURE INPUT USING THE DEALER TEST MODE
- Ignition ON.
- Enter the IC dealer test mode.
- NOTE: The display below uses xxx's to represent a numeric or alpha-numeric value. The value may display the same amount of characters represented by the xxx's or there may be more/less depending on the type of display and that the minus symbol in parenthesis only appears if the temperature is below 0°C. For example: Ct xxx may display Ct 20. Note that there were 3 x's in the display description but only 2 digits in the actual display.
- Scroll through the displays to Ct xxx.
- Start the engine and run the engine through a variety of engine temperatures.
- NOTE: The coolant temperature should range between 0-59°C (32-138°F) with the gauge in the cold (C) range, between 60-120°C (140-248°F) with the gauge in the normal or mid-range and above 123°C (253°F) with the gauge in the hot (H) range.
- Monitor the engine coolant temperature input to the IC and the coolant temperature gauge indication.
- Does the engine coolant input agree with the position of the temperature gauge indication?
Yes
The temperature gauge is operating correctly at this time.
No
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.
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