GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2007 🢒 Terraza Ext. 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 Engine Coolant Temperature Indicator Diagnosis

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

Circuit/System Description

Ignition voltage and ground are supplied to the instrument panel cluster (IPC). When the ignition is turned ON, the IPC tests each indicator to verify the features are working properly.

Reference Information

Schematic Reference

Engine Cooling Schematics

Connector End View Reference

    •  Engine Control Module Connector End Views
    •  Electrical Center Identification Views
    •  Engine Controls Connector End Views
    •  Cooling System Component Views
    •  Cooling System Connector End Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions
    •  Scan Tool Output Controls

Circuit/System Verification
  1. Ensure the engine is below operating temperature.
    2. ⇒If engine coolant is above operating temperature, repair the engine overheating condition. Refer to Engine Overheating .
  2. Observe the vehicle DTC information with a scan tool.
    3. ⇒If DTC B1000, B1327, or B1328 are set, diagnose those DTCs first.
  3. Perform the Lamp Test in the IPC special functions. The coolant indicator should turn ON and OFF with each command.
    4. ⇒If the indicator does not turn ON and OFF with each command, replace the IPC.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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