Pinpoint Test E: Incorrect Temperature Gauge Indication

Instrumentation, Message Center and Warning Chimes

Pinpoint Test E: Incorrect Temperature Gauge Indication

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). 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 U0100:00 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 U0401:81 and defaults the temperature gauge to cold (C).

NOTE: If DTC U0100:00 sets in the IPC (Instrument Panel Cluster), other observable symptoms may be an inoperative tachometer, speedometer or odometer.

This pinpoint test is intended to diagnose the following:

- PCM concern

- IPC (Instrument Panel Cluster)

PINPOINT TEST E : INCORRECT TEMPERATURE GAUGE INDICATION

E1 CHECK FOR CORRECT OPERATION OF THE COOLING SYSTEM

- Verify the engine cooling system and thermostat are functioning correctly.

Does the engine cooling system and thermostat operate correctly?

Yes
GO to E2.

No
REFER to Cooling System &/or Engine Block Heater.

E2 RETRIEVE THE RECORDED DTCs FROM THE PCM KOEO (Key ON Engine OFF) SELF-TEST

- Check the recorded PCM DTCs from the KOEO (Key ON Engine OFF) self-test.

Are any DTCs recorded?

Yes
REFER to Computers and Control Systems Information.

No
GO to E3.

E3 RETRIEVE THE RECORDED DTCs FROM THE IPC (Instrument Panel Cluster) SELF-TEST

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

Are any DTCs recorded?

Yes
For DTC U0100:00, GO to Pinpoint Test AQ Pinpoint Test AQ: DTC U0100:00.

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

No
GO to E4.

E4 CARRY OUT THE TEMPERATURE GAUGE ACTIVE COMMAND USING THE SCAN TOOL

- Ignition ON.

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

- NOTE: Set the scan tool to 0 or full cold before beginning this step.

Select the IPC (Instrument Panel Cluster) temperature gauge (ENGCOOLNT) active command. Command the temperature gauge according to the following table:

Base IPC (Instrument Panel Cluster)

Scan Tool Command Gauge Position 0% (-60-38°C [-76-100°F]) Beginning of cold (C) (fill color blue) 15% (59°C [138°F]) End of cold (C) (fill color blue) 35% (79°C [174°F]) Just below the center of the gauge (mid-range, fill color gray) 65% (120°C [248°F]) Just below the beginning of hot (H) (fill color gray) 80% (121°C [250°F]) Just above hot (H) (fill color red)

Optional IPC (Instrument Panel Cluster)

Scan Tool Command Gauge Position 0% (-60-38°C [-76-100°F]) Full cold (C) 15% (59°C [138°F]) Beginning of the normal range 45% (83-109°C [181-228°F]) Center of the gauge 85% (120°C [248°F]) End of the normal range 95% (122°C [252°F]) Hot (H) (red line)

Does the temperature gauge operate according to the above specifications?

Yes
GO to E5.

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

E5 CHECK THE PCM TEMPERATURE PID

NOTE: The coolant temperature should range between 0-59°C (32-138°F) with the gauge in the cold (C) range, between 60-120°C (140-248°F) with the gauge in the normal or mid-range and above 121°C (250°F) with the gauge in the hot (H) range.

- Enter the following diagnostic mode on the scan tool: PCM DataLogger.

- Ignition ON.

- Select the PCM temperature PID (CHT). With the engine running, monitor the PCM temperature PID.

Does the PCM PID agree with the position of the temperature gauge indication?

Yes
The temperature gauge is operating correctly at this time.

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