Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

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

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

The security indicator will be illuminated.

Schematic Reference

Theft Deterrent System Schematics

Connector End View Reference

Theft Deterrent System Connector End Views

Description and Operation

Vehicle Theft Deterrent (VTD) Description and Operation

Electrical Information Reference

Scan Tool Reference

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.

1. Verify that DTC B3055 or DTC B3060 is not set as a current DTC.

⇒	If DTC B3055 or DTC B3060 is set, proceed with those diagnostic prior to performing the diagnostics for DTC B3967. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .

2. 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 only one key results in inoperative starting and DTC B3976 is set as current, replace the suspect key.

⇒	If all available keys result in inoperative starting and DTC B3976 is set as current, replace the TDM.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Important: Because of how vehicle key information and theft deterrent passwords are stored within the TDM, the Set Up a New Theft Deterrent Module procedure must be performed prior to the removal and replacement of the TDM if the vehicle keys are being reused. Performing the setup procedure first allows the scan tool to extract the key information and passwords from the old TDM prior to its removal. Failure to perform this step will result in the failure to learn the existing vehicle keys and new vehicle keys will be required when replacing the TDM.