GM Service Manual Online
For 1990-2009 cars only

Diagnostic Fault Information

Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit/System Description

The instrument panel cluster (IPC) displays the engine coolant temperature as determined by the powertrain control module (PCM) or the engine control module (ECM). The IPC receives a serial data message from the PCM indicating the engine coolant temperature.

Reference Information

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Instrument Panel, Gages, and Console 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

Circuit/System Testing

  1. Ignition ON, with the scan tool, perform the IPC Gage Sweep Test in the IPC Output Controls. Verify that all gage dials move from minimum to the maximum value and back to the gage minimum value.
  2. If the engine coolant temperature (ECT) gage does not perform the IPC Gage Sweep Test, replace the IPC.

Repair Instructions

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

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