Pinpoint Test D: The Temperature Gauge Is Inoperative

Instrumentation, Message Center and Warning Chimes

Pinpoint Test D: The Temperature Gauge Is Inoperative

Normal Operation

The PCM uses the Cylinder Head Temperature (CHT) sensor to measure the engine temperature. The Instrument Panel Cluster (IPC) receives the engine temperature data from the PCM over the High Speed Controller Area Network (HS-CAN) communication bus. The IPC (Instrument Panel Cluster) monitors the engine temperature data received from the PCM and commands the temperature gauge indication with a corresponding movement of the pointer.

If the engine temperature data is missing for 5 seconds or less or if the IPC (Instrument Panel Cluster) receives invalid engine temperature data for 5 seconds or less, the IPC (Instrument Panel Cluster) defaults the temperature gauge to the last setting, based upon the last known good temperature status message. If the IPC (Instrument Panel Cluster) does not receive the engine temperature status message from the PCM for more than 5 seconds, the IPC (Instrument Panel Cluster) sets DTC U0100:87 in continuous memory and defaults the temperature gauge to cold (C). If the engine temperature data is deemed invalid by the IPC (Instrument Panel Cluster) for 5 seconds or more, the IPC (Instrument Panel Cluster) sets DTC U0401:68 and defaults the temperature gauge to cold (C).

NOTE: If DTC U0100:87 is set in the IPC (Instrument Panel Cluster) , other observable symptoms can be an inoperative tachometer, speedometer or odometer.

This pinpoint test is intended to diagnose the following:

- PCM

- IPC (Instrument Panel Cluster)

PINPOINT TEST D : TEMPERATURE GAUGE INOPERATIVE

D1 RETRIEVE THE RECORDED PCM DTCs FROM THE KOEO (Key ON Engine OFF) 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 Information.

No
GO to D2.

D2 RETRIEVE THE RECORDED DTCs FROM THE IPC (Instrument Panel Cluster) SELF-TEST

- Check for recorded DTCs from the IPC (Instrument Panel Cluster) self-test.

Are any DTCs retrieved?

Yes
For DTC U0100:87, GO to Pinpoint Test AQ Pinpoint Test AQ: DTC U0100:87.

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

No
GO to D3.

D3 CARRY OUT THE IPC (Instrument Panel Cluster) COOLANT TEMPERATURE GAUGE ACTIVE COMMAND USING THE SCAN TOOL

- Ignition ON.

- Enter the following diagnostic mode on the scan tool: IPC (Instrument Panel Cluster) DataLogger.

- Select the IPC (Instrument Panel Cluster) temperature gauge (ENGCOOLNT) active command on and off while monitoring the temperature gauge.

Does the temperature gauge start at C (cold) when at 0%, and move to H (hot) at 100%?

Yes
INSTALL a new PCM. TEST the system for normal operation.

No
INSTALL a new IPC (Instrument Panel Cluster). REFER to Instrument Panel Cluster (IPC) . TEST the system for normal operation.