Engine Coolant Temperature Gage Inaccurate or Inoperative

Engine Coolant Temperature Gage Inaccurate or Inoperative

Diagnostic Instructions

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

Circuit/System Description

The instrument panel cluster (IPC) displays the engine coolant temperature as determined by the engine control module (ECM). The ECM sends the temperature data via high speed GMLAN serial data to the body control module (BCM). The BCM then sends the information via low speed GMLAN to the IPC in order to display the engine temperature.

Circuit/System Testing

1. Ignition ON, perform the engine coolant gage sweep test with the scan tool.

• If the engine coolant gage does not sweep from its low to high position, replace the instrument panel cluster (IPC).

Repair Instructions

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

Control Module References for IPC replacement, setup, and programming