Pinpoint Test Z: The Engine Over-Temperature Message Center Warning Indicator Is Never/Always On
Instrumentation, Message Center and Warning Chimes
Pinpoint Tests
Pinpoint Test Z: The Engine Over-Temperature Message Center Warning Indicator Is Never/Always On
Normal Operation
There are 3 separate situations when the Instrument Cluster (IC) receives a message to turn on the engine over-temperature message center warning indicator; a high engine temperature condition, fail-safe cooling 1 or fail-safe cooling 2 state. The PCM sends the applicable message to the IC over the High Speed Controller Area Network (HS-CAN) communication bus whenever any of the 3 conditions exist. The PCM receives the engine coolant temperature status through hardwired circuitry to the Cylinder Head Temperature (CHT) sensor. If a high engine temperature condition exists, the PCM sends a message to the IC to turn on the engine over-temperature message center warning indicator. If a fail-safe warning condition exists, the PCM sends a message to the IC to flash the engine over-temperature message center warning indicator.
If the IC does not receive the engine temperature or fail-safe cooling status or if the data is deemed invalid by the IC for more than 5 seconds, the message is considered missing and the IC sets DTC U0100 and defaults the temperature gauge to the cold (C) stop and the engine over-temperature message center warning indicator on.
- DTC U2199 (Invalid Engine Coolant Temperature Data) - a continuous DTC that sets if the IC receives invalid engine temperature data from the PCM. The IC defaults the temperature gauge to the cold (C) stop and turns on the engine over-temperature message center warning indicator.
This pinpoint test is intended to diagnose the following:
- PCM
- Message center concern
PINPOINT TEST Z: THE ENGINE OVER-TEMPERATURE MESSAGE CENTER WARNING INDICATOR IS NEVER/ALWAYS ON
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Z1 CHECK THE DOOR AJAR MESSAGE CENTER WARNING INDICATOR
- Close all doors, liftgate and liftgate glass.
- Ignition ON.
- Open the driver door while monitoring the door ajar message center warning indicator.
- Does the driver door ajar message center warning indicator turn off with the driver door closed and turn on with the driver door open?
Yes
GO to Z2.
No
GO to Pinpoint Test A. Pinpoint Test A: The Instrument Cluster (IC) Is Inoperative
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Z2 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 U0100, GO to Pinpoint Test AT. Pinpoint Test AT: DTC U0100
For DTC U2199, RETRIEVE and REPAIR all non-network DTCs in the PCM and other modules on the network. REFER to Computers and Control Systems and Multifunction Electronic Modules Diagnostic Trouble Code (DTC) Chart for a list of all DTCs.
If DTC U0100 and U2199 are both recorded, REFER to Module Communications Network Testing and Inspection to diagnose the communication network.
No
GO to Z3.
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Z3 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 DTCs recorded?
Yes
REFER to Computers and Control Systems.
No
INSTALL a new PCM. REFER to Electronic Engine Controls Service and Repair. TEST the system for normal operation.
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