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 information switches are normally open momentary switches. Power is provided to the driver information center (DIC) switches via the instrument panel cluster (IPC) ignition 1 voltage circuit. The IPC ignition 1 voltage circuit is fused in the body control module (BCM). The IPC interfaces with the DIC switches via 3 discreet circuits. The switch input to the cluster is pulled low or grounded when a switch is activated. The IPC reads the voltage at the analog input to determine which switch(es) is pressed. The switch input to the cluster is set up in a resistor ladder format. The DIC switches include the PERSONALIZATION, SET/RESET, TRIP/FUEL, AND VEHICLE INFO switches.

Reference Information

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Displays and Gages 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 OFF, disconnect the harness connector at the DIC switch assembly.
  2. Ignition OFF, test for less than 1 ohm of resistance between the ground circuit and ground.
  3. If greater than 1 ohm, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify all of the scan tool DIC Switch parameters are Inactive.
  5. If any are not Inactive, test the signal circuit for a short to ground. If the circuit tests normal, replace the IPC
  6. Ignition ON, install a 3-amp fused jumper wire between the signal circuit and ground. Verify all of the scan tool DIC Switch parameters are Active.
  7. If any are not Active, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the IPC.
  8. If all the circuits test normal, test or replace the DIC switch assembly.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for IPC replacement, setup, and programming