GM Service Manual Online
For 1990-2009 cars only

DTC Descriptor

DTC B3976 48 : Unconfigured Transponder Key Theft/Security Data Not Programmed

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle .

Circuit/System Description

When the theft deterrent module (TDM) is in the learn coded key or learn more keys mode, the TDM checks the current key to ensure it has been configured as a correct vehicle key.

Conditions for Running the DTC

    • Ignition is in the ACC or ON position.
    • The TDM is in the learn coded key or learn more keys mode.

Conditions for Setting the DTC

The TDM has determined the current key is not configured as a correct vehicle key.

Action Taken When the DTC Sets

The security warning lamp will illuminate.

Conditions for Clearing the DTC

    • A current DTC will clear when the TDM detects a correctly configured vehicle key.
    • A history DTC will clear after 100 fault-free ignition cycles.
    • The DTC can be cleared using a scan tool.

Reference Information

Description and Operation

Theft Systems Description and Operation

Scan Tool Reference

Control Module References

Circuit/System Testing

Important: When using this diagnostic, more than one vehicle key is required to ensure proper diagnosis. If more than one key is not available at the time of service, contact the customer and ask if any other keys can be provided for service. If unavailable, a new second key can be created.

While viewing DTCs with a scan tool, attempt to start the vehicle using all of the available keys. The vehicle should start with all available keys.

If any key results in inoperative starting and DTC B3976 is set as current, replace the suspect key.

Repair Instructions

Perform the Diagnostic Repair Verification .

    •  Replacing Keys
    •  Adding Keys
    •  Control Module References .