Pinpoint Tests AA: The Over-Temperature Warning Indicator Is Never/Always On

Instrumentation and Warning Chimes

Pinpoint Test

Pinpoint Test AA: The Over-Temperature Warning Indicator Is Never/Always On

Normal Operation

The over-temperature status is sent from the PCM to the Instrument Cluster (IC) over the High Speed Controller Area Network (HS-CAN) communication bus. During an engine overheat condition, the PCM enters into the failsafe mode and sends a signal to the IC to turn on the over-temperature warning indicator. The IC sets DTC U0100 in continuous memory if the over-temperature status message is missing for more than 5 seconds and the IC turns off the failsafe warning indicator.

This pinpoint test is intended to diagnose the following:

- PCM
- IC



PINPOINT TEST AA: THE OVER-TEMPERATURE WARNING INDICATOR IS NEVER/ALWAYS ON

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AA1 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO SELF-TEST


- Retrieve the recorded DTCs from the PCM Key ON Engine OFF (KOEO) self-test.
- Are any DTCs retrieved?

Yes
REFER to Computers and Control Systems Information.

No
GO to AA2.

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AA2 RETRIEVE THE RECORDED DTCs FROM THE IC SELF-TEST


- Retrieve the recorded DTCs from the IC self-test.
- Is DTC U0100 retrieved?

Yes
GO to Pinpoint Test AK. Pinpoint Tests AK: DTC U0100

No
GO to AA3.

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AA3 CARRY OUT THE IC INDICATOR LAMP COMMAND USING THE SCAN TOOL


- Ignition ON.
- Enter the following diagnostic mode on the scan tool: IC DataLogger.
- Select the IC over-temperature indicator (OVTEMP_LMP) active command. Command the over-temperature warning indicator on then off. Observe the over-temperature warning indicator.
- Does the over-temperature warning indicator turn on when commanded on and turn off when commanded off?

Yes
If the over-temperature warning indicator is never on, the system is operating correctly at this time.

If the over-temperature warning indicator is always on, INSTALL a new PCM. REFER to Computers and Control Systems. 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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