Pinpoint Test C: Incorrect Temperature Gauge Indication
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test C: Incorrect Temperature Gauge Indication (Except Hybrid)
Normal Operation
The PCM uses the Engine Coolant Temperature (ECT) sensor to measure the engine coolant temperature on the 3.0L engine and the Cylinder Head Temperature (CHT) sensor on the 2.5L engine. The Instrument Cluster (IC) receives the engine coolant temperature data from the PCM over the High Speed Controller Area Network (HS-CAN) communication bus. The IC monitors the engine coolant temperature data received from the PCM and commands the temperature gauge indication with a corresponding movement of the pointer.
If the IC receives invalid engine coolant temperature data from the PCM for 5 seconds or less, the IC defaults the temperature gauge to the last setting, based upon the last known good temperature status message. If the IC does not receive the engine coolant temperature status message from the PCM or if the data received is deemed invalid for more than 5 seconds, the IC sets DTC U0100 in continuous memory and defaults the temperature gauge to cold (C).
NOTE: If DTC U0100 is set in the IC, other observable symptoms may be an inoperative speedometer, tachometer or odometer.
This pinpoint test is intended to diagnose the following:
- CHT sensor
- ECT sensor
- PCM concern
- IC
PINPOINT TEST C: INCORRECT TEMPERATURE GAUGE INDICATION (EXCEPT HYBRID)
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C1 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST
- Check for recorded IC DTCs from the self-test.
- Is DTC U0100 recorded?
Yes
Go To Pinpoint Test AS. Pinpoint Tests AS: DTC U0100
No
GO to C2.
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C2 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 C3.
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C3 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: 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 121°C (249°F) with the gauge in the hot (H) range.
- Select the IC temperature gauge (ENGCOOLNT) active command. Command the temperature gauge to 50°C (122°F), 100°C (212°F) and 125°C (257°F) while monitoring the gauge.
- Does the temperature begin in approximately the center of the cold (C) range, move to approximately the center of the gauge then to the full hot (H) position?
Yes
GO to C4.
No
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.
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C4 CHECK THE COOLANT TEMPERATURE INPUT USING THE IC DEALER TEST MODE
- Ignition ON.
- Enter Instrument Cluster (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 will only appear if the temperature is below 0°C. For example: (-)xxx C (base cluster) or TEMP GAUGE/(-)xxx DEG C (message center cluster) may display 20 C or TEMP GAUGE/20 DEG C. Note that there were 3 x's in the display description but only 2 digits in the actual display.
- Scroll down to (-)xxx C (base cluster) or TEMP GAUGE/(-)xxx DEG C (message center cluster).
- 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 121°C (249°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
GO to C5.
No
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.
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C5 CHECK THE PCM TEMPERATURE PIDs
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 121°C (249°F) with the gauge in the hot (H) range.
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Select the PCM temperature PID (CHT). With the engine running, monitor the PCM temperature PID.
- Does the PCM PID agree with the position of the temperature gauge indication?
Yes
INSTALL a new CHT sensor or ECT sensor. 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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