GM Service Manual Online
For 1990-2009 cars only

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit/System Description

The driver information switches are normally open momentary switches. Power is provided to the driver information center (DIC) switches via the IPC ignition 1 voltage circuit. The IPC ignition 1 voltage circuit is fused in the body control module (BCM). The instrument panel cluster (IPC) interfaces with the DIC switches via two 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 INFO and the SELECT/RESET switches. A simultaneous press and hold of the INFO and SELECT/RESET switch activates the MENU switch. The MENU switch is the third embedded switch used to activate the various DIC menus.

Reference Information

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

    •  Instrument Panel, Gages, and Console Connector End Views
    •  Steering Wheel and Column 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.

    •  Steering Wheel Control Switch Assembly Replacement
    •  Control Module References for PCM or IPC replacement, setup, and programming