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 and overview of each diagnostic category.

DTC Descriptor

DTC B3031: Security System Controller In Learn Mode

Circuit/System Description

When learning a vehicle key, the theft deterrent module (TDM) is placed in learn mode. DTC B3031 will set automatically as an indicator that the system is in learn mode and not as a fault indicator. Once the coded key is learned, learn mode will be exited and the DTC cleared. If the TDM does not exit learn mode, B3031 will remain current and indicate a fault.

Conditions for Running the DTC

The immobilizer system is in learn mode.

Conditions for Setting the DTC

DTC B3031 will set any time the TDM enters learn mode.

Action Taken When the DTC Sets

The security indicator will illuminate.

Conditions for Clearing the DTC

    • A current DTC will be cleared upon the successful exit of learn mode.
    • A history DTC will be cleared after 100 malfunction-free ignition cycles.

Reference Information

Schematic Reference

Immobilizer Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Immobilizer Description and Operation

Electrical Information Reference

    •  Testing for Intermittent Conditions and Poor Connections
    •  Circuit Testing
    •  Wiring Repairs
    •  Connector Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Important: When performing a 10 Minute Relearn Procedure, all keys not learned at that time will be erased and not be recognized. Perform the Adding Keys procedure on all keys or instruct the customer how to perform the Adding Keys procedure should all vehicle keys not be present at the time of repair.

  1. Verify DTC B3055 is not set as current.
  2. If DTC B3055 is set as current, refer to DTC B2947, B2948, B2955, B2960, or B3055 .
  3. Perform the 10 Minute Vehicle Key Relearn procedure. Refer to Replacing Keys . The TDM should exit learn mode and DTC B3031 should clear.
  4. If the TDM does not exit learn mode, replace the TDM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for TDM replacement, setup, and programming