Pinpoint Test D: The Temperature Gauge Is Inoperative
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test D: The Temperature Gauge Is Inoperative
Normal Operation
The PCM uses the Cylinder Head Temperature (CHT) sensor to measure the Engine Coolant Temperature (ECT). The Instrument Cluster (IC) receives the ECT data from the PCM over the High Speed Controller Area Network (HS-CAN) communication bus. The IC monitors the ECT data received from the PCM and commands the temperature gauge indication with a corresponding movement of the pointer.
If the ECT data is missing for 5 seconds or less or if IC receives invalid ECT data 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 ECT status message from the PCM for more than 5 seconds, the IC sets DTC U0100 in continuous memory and defaults the temperature gauge to cold (C). If the ECT data is deemed invalid by the IC for 5 seconds or more, the IC sets DTC U2199 and defaults the temperature gauge to cold (C).
NOTE: If DTC U0100 is set in the IC, other observable symptoms may be an inoperative tachometer, speedometer or odometer.
- DTC U2199 (Invalid Engine Coolant Temperature Data) - sets in continuous memory in the IC if the IC receives invalid engine coolant temperature data from the PCM for 5 seconds or more.
This pinpoint test is intended to diagnose the following:
- PCM concern
- IC
PINPOINT TEST D: THE TEMPERATURE GAUGE IS INOPERATIVE
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D1 RETRIEVE THE RECORDED DTCs FROM BOTH CONTINUOUS AND ON-DEMAND PCM SELF-TESTS
- Check the recorded PCM DTCs from the continuous and on-demand self-tests.
- Are any DTCs recorded?
Yes
REFER to Computers and Control Systems Information.
No
GO to D2.
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D2 CARRY OUT THE 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 in 10% increments while monitoring the gauge.
- Does the temperature gauge start at cold (C), move to full hot (H) and return to cold (C)?
Yes
GO to D3.
No
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.
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D3 RETRIEVE THE RECORDED DTCs FROM BOTH THE CONTINUOUS AND ON-DEMAND IC SELF-TESTS
- Check for recorded IC DTCs from the continuous and on-demand self-tests.
- Are any DTCs recorded?
Yes
For DTC U0100, Go To Pinpoint Test AE. Pinpoint Tests AE: DTC U0100
For all other DTCs, REFER to DTC Charts. Instrumentation, Message Center and Warning Chimes
No
INSTALL a new IC. REFER to Instrument Cluster (IC) Instrument Cluster (IC). TEST the system for normal operation.
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