Engine Coolant Temperature Indicator Malfunction

Engine Coolant Temperature Indicator Malfunction

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

Circuit/System Description

The instrument panel cluster (IPC) illuminates the TEMP indicator when the engine control module (ECM) determines that the coolant temperature is more than 128°C (262°F). The IPC receives a discrete input from the ECM requesting illumination.

The IPC illuminates the TEMP indicator during the display test at the start of each ignition cycle.

Reference Information
Schematic Reference

Instrument Cluster Schematics (Instrument Cluster Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

* Instrument Cluster Description and Operation (Description and Operation)
* Cooling System Description and Operation (Cooling System Description and Operation)

Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Programming and Relearning (Programming and Relearning) for scan tool information

Circuit/System Verification

1. Ignition ON, verify that the engine coolant temperature indicator illuminates during the self test when the ignition is turned ON.

• If the temperature indicator does not illuminate, replace the IPC.

2. Ignition ON, verify that the scan tool Engine Coolant Temperature (ECT) Sensor parameter is within the temperature range shown on the engine coolant temperature gage.

• If not within the specified range, replace the IPC.

3. If the temperature gage is normal, refer to Engine Overheating (Engine Overheating).

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Programming and Relearning (Programming and Relearning) for the IPC replacement, setup, and programming