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

When an ignition key is inserted into the ignition lock cylinder and the ignition is switched ON, the transponder embedded in the head of the key is energized by the exciter coils surrounding the ignition lock cylinder. The energized transponder transmits a signal that contains its unique value, which is received by the theft deterrent module (TDM). The TDM then compares this value to a value stored in memory. If the values match, the TDM will send the fuel enable password via the serial data circuit to the engine control module (ECM). If the transponders unique value is incorrect, the TDM will send the fuel disable password to the ECM.

Ignition is in the Accessory or Run position.

The TDM is unable to measure the ignition key transponder value.

A damaged or missing transponder, a non-Passkey III+ (PK3+) key, or a damaged exciter will cause DTC B3055 to set.

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. Inspect all available vehicle keys that they are correct PK3+ keys and that the molded head is undamaged.

⇒	If damaged or not a correct PK3+ key, replace the key.

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 B3055 is set as current, replace the suspect key.

⇒	If all available keys result in inoperative starting and DTC B3055 is set as current, replace the TDM.

Perform the Diagnostic Repair Verification after completing the repair.

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.