GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The instrument panel cluster (IPC) supplies 54 volts to the instrument panel module (IPM) for operation of the HVAC vacuum fluorescent (VF) display. The IPC performs a diagnostic test on the 54V VF display supply every 100 milliseconds.

Conditions for Running the DTC

    • The battery voltage is greater than 9 volts.
    • The 54V VF display supply is active.

Conditions for Setting the DTC

The current draw by the IPM on the 54V VF display supply circuit is greater than 100 milliamps for 5 diagnostic tests.

Action Taken When the DTC Sets

    • For 2.5 seconds, the IPC enters recovery diagnostic mode. The IPC continues to check the circuit for a reduction in current draw.
    • After 2.5 seconds, the IPC disables the 54V VF display supply.

Conditions for Clearing the DTC

During the recovery diagnostic mode, the current draw by the IPM on the 54V VF display supply circuit is less than 95 milliamps for 5 diagnostic tests.

Diagnostic Aids

    • An intermittent condition can be caused by the following:
       - The wiring harness is routed incorrectly.
       - The insulation of the wiring is rubbed through.
    • Following successful diagnosis, cycle the ignition so that initialization of the circuit occurs.

Step

Action

Yes

No

Schematic Reference: Interior Lights Dimming Schematics

Connector End View Reference: Lighting Systems Connector End Views , Body Control System Connector End Views , or Instrument Panel, Gages, and Console Connector End Views

1

Did you perform the Lighting Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Test the 54V VF display supply circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 5

Go to Step 3

3

Inspect for poor connections at the harness connector of the instrument panel cluster (IPC). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 5

Go to Step 4

4

Replace the IPC. Refer to Instrument Cluster Replacement in Instrument Panel, Gages and Console.

Did you complete the replacement?

Go to Step 5

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5

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC Reset?

Go to Step 2

System OK