GM Service Manual Online
For 1990-2009 cars only

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

The driver efficiency gage shows when the vehicle is operating at a fuel efficient point. There are several zones on the gage indicating different levels of efficiency. The gage shall indicate fuel efficiency when the engine is running and will be set at the minimum scale position when the ignition transitions to a mode other than when the engine is running. The gage will set at its half scale position when there is a loss of communication. The engine control module (ECM) provides information to the instrument panel cluster (IPC) for the driver efficiency gage via the serial data circuit.

Reference Information

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Instrument Cluster Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Ignition ON, perform the driver efficiency gage sweep test with the scan tool. Verify that the driver efficiency gage sweeps from its low to high position.

If the driver efficiency gage does not sweep from its low to high position, replace the IPC.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for IPC replacement, setup, and programming