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 send 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 engine over-temperature status message is missing or invalid for less than 5 seconds, the engine over-temperature warning indicator remains in the last on/off state, based upon the last known good engine over-temperature status message received.

If the engine over-temperature status message is missing for more than 5 seconds, the IC sets DTC U0100 in continuous memory and defaults the engine over-temperature warning indicator on.

If the engine coolant temperature data is invalid for more than 5 seconds, the IC sets DTC U2199 and defaults the engine over-temperature message center warning indicator on.

NOTE: If DTC U0100 is set in the IC, other observable symptoms may be an inoperative tachometer, temperature gauge or odometer.

This pinpoint test is intended to diagnose the following:

- PCM concern
- 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 MESSAGE CENTER WARNING INDICATOR FUNCTION


- Close all doors and hood.
- Ignition ON.
- Open the driver door while monitoring the door ajar message center displays.
- Does the door ajar message center warning indicator display?

Yes
GO to Z2.

No
GO to Pinpoint Test AF Pinpoint Tests AF: The Message Center Is Not Operating Correctly

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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 AP. Pinpoint Tests AP: DTC U0100

For all other DTCs, REFER to DTC Charts. Instrumentation, Message Center and Warning Chimes

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 Computers and Control Systems. TEST the system for normal operation.

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