Engine Coolant Temperature Gage Inaccurate or Inoperative

ENGINE COOLANT TEMPERATURE GAGE INACCURATE OR INOPERATIVE

DIAGNOSTIC FAULT INFORMATION

IMPORTANT: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Testing and Inspection

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 GMLAN serial data circuit to the body control module (BCM). The BCM sends the GMLAN message to the IPC in order to control the engine temperature gage and 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

IMPORTANT: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

Control Module References for IPC replacement, setup, and programming.