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

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

DIC Switch Signal

1

1

P3567

P3567

DIC Select Switch Signal

1

1

1

P3567

DIC Switch Low Reference

--

1

--

--

DIC Switch Ground

--

1

--

--

1. Driver Information Center (DIC) Switch Malfunction

Circuit/System Description

The driver information center (DIC) switch is a multiplexed switch that functions as a DIC/dimmer switch. The DIC switch is also used for the head-up-display (HUD) (if equipped). The switch then functions as the HUD/DIC/Dimmer switch. The instrument panel cluster (IPC) only monitors the DIC switch inputs. The dimmer switch is monitored by the instrument panel module (IPM) and the HUD switch inputs is monitored by the HUD module. Battery power is provided to the DIC switch via the instrument panel cluster (IPC). The IPC also provides the DIC switch with a ground reference. The switch input to the IPC is pulled low or grounded when a switch is activated. The DIC switch is a momentary contact switch that connects a series of resistors in a resistor ladder format. The IPC monitors the DIC switch signal circuit to determine the DIC switch inputs. Each switch state - INFO UP, INFO DOWN, INFO RESET, ENGLISH/METRIC, TRIP RESET- corresponds to a certain resistance value. The IPC determines the switch pressed by the voltage drop across the resistors.

The TRIP A/B switch is monitored on a separate circuit provided by the IPC.

Reference Information

Schematic Reference

Instrument Cluster Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Driver Information Center (DIC) 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, verify that when the DIC switches are pressed and released the DIC scan tool parameters toggle between Active and Inactive.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the DIC switch assembly.
  2. Ignition OFF, test for less than 1 ohm between the low reference circuit terminal 8 and ground.
  3. If greater than the specified range, test the low reference circuit for an open/high resistance.
  4. Ignition OFF, test for less than 5 ohms between the ground circuit terminal 12 and ground.
  5. If greater than the specified range, test the ground circuit for an open/high resistance.
  6. Ignition ON, verify that all of the scan tool DIC Switch parameters are Inactive.
  7. If any are not Inactive, test the signal circuit terminal 9 or terminal 10 for a short to ground. If the circuit tests normal, replace the IPC.
  8. Ignition ON, install a 3-amp fused jumper wire between the signal circuit terminal 9 and the low reference circuit terminal 8. Verify the scan tool DIC Switch parameters, except the Trip A/B. parameter, are Active.
  9. 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.
  10. Ignition ON, install a 3-amp fused jumper wire between the signal circuit terminal 10 and ground. Verify the scan tool Trip A/B. parameter is Active.
  11. If not Active, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the IPC.
  12. 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 the IPC replacement, setup and programming.
    •  Instrument Panel Lamp Dimmer Switch Replacement