GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The instrument panel cluster (IPC) supplies a 5 volt signal and a ground circuit for the PASS-Key® system. This allows the IPC to detect PASS-Key® resistance values. Inserting the PASS-Key® ,with resistor pellet, in the ignition lock cylinder completes the PASS-Key® circuit. Contacts in the ignition lock cylinder mate with the pellet contacts. The IPC compares the resistance value of the key pellet to the valid resistance programmed into the IPC. If the proper resistance value is read, the IPC allows the engine to start. If the resistance value is incorrect, a malfunction is present and a DTC will set. This DTC indicates an internal module malfunction.

Conditions for Setting the DTC

The presence of this DTC indicates that the key code or password stored in the IPCs memory is invalid.

Conditions for Clearing the DTC

    • This DTC requires an ignition cycle in order to change from current to history.
    • The IPC detects a valid PASS-Key® resistance value on the PASS-Key® signal circuit.
    • A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.
    • Use a scan tool.

Diagnostic Aids

If this DTC is set as current, the IPC must be replaced.

Step

Action

Yes

No

1

Did you perform A Diagnostic System Check-Theft Deterrent?

Go to Step 2

Go to Diagnostic System Check - Theft Deterrent

2

  1. Install a scan tool.
  2. Select the Display DTCs function for the IPC.

Does the scan tool display DTC B2783 as a curerent DTC?

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

3

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

Did you complete the repair?

Go to Step 4

--

4

  1. Use a scan tool in order to clear the DTCs.
  2. Attempt to start the vehicle.

Does the DTC reset?

Go to Step 2

System OK