Engine Coolant Temperature Indicator Malfunction

Engine Coolant Temperature Indicator Malfunction

Diagnostic Instructions

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

Circuit/System Description

The instrument panel cluster (IPC) illuminates the engine coolant temperature indicator when the powertrain control module (PCM)/engine control module (ECM) determines that the coolant temperature is more than 128°C (262°F). The IPC receives a serial data message from the PCM/ECM requesting the illumination of the engine coolant temperature indicator.

Reference Information
Schematic Reference

Engine Cooling Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Cooling System Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (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.

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