B2723

Diagnostic Chart:

CIRCUIT DESCRIPTION
When an ignition key is inserted into the ignition lock cylinder, the transponder that is embedded in the head of the key is energized by the exciter coils that surround the ignition lock cylinder. The energized transponder transmits a signal that contains its unique value which is received by the VTD (Pass Key III(R)) module. The VTD module then compares this value to a value stored in memory (learned key code). If the value is correct the VTD module sends the enable password via the class 2 serial data circuit to the PCM.

CONDITIONS FOR RUNNING THE DTC
The ignition switch must be in the RUN position. The VTD module cannot have a current DTC B1327.

CONDITIONS FOR SETTING THE DTC
The VTD (Pass key III(R)) module is unable to measure the ignition key transponder value for 1 second. This may be due to a damaged or missing transponder pellet, a non Pass Key III(R) key, or a damaged exciter. If the conditions occur after the engine is running, setting the DTC may take up to 30 seconds.
Refer to the Important statement below.

ACTION TAKEN WHEN THE DTC SETS

IMPORTANT: If the VTD module is unable to measure the ignition key transponder value for 30 consecutive seconds, after the vehicle has started, the module will enter a fail enable state. The vehicle will not stall or stop running. If the VTD module is in a fail enable state when the ignition is turned to OFF, the VTD module will remain "fail enabled" until the next time the vehicle is started. If the VTD module is 'fail enabled", the Pass key III(R) system is NOT active and the vehicle wilt start. The module WILL send its enable password even if a transponder value is not received. The VTD module will remain "fail enabled" until the module measures a valid key transponder value.

1. The VTD module sends a class 2 message containing a disable password to the PCM.
2. The vehicle will not start.
3. The VTD Module sends a class 2 message to the instrument cluster in order to illuminate the SECURITY indicator on steady.

CONDITIONS FOR CLEARING THE MIL/DTC
The VTD module clears the current status of the DTC when the module senses a key code from the exciter. If the code is not from a learned key, a DTC B2721 will be set.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table:
2. The key must be a Pass Key III(R) transponder key with an operating transponder for the system to work.
3. The only method to confirm whether the transponder in the key or the VTD (Pass Key III(R)) module is malfunctioning is to try an alternative component in the system. The vehicle was delivered with 4 keys.
4. The possibility is unlikely that more than one key will be defective. If all keys do not work, the VTD (Pass Key III(R)) module must be malfunctioning.
5. If the vehicle has a malfunctioning VTD (Pass Key III(R)) module that malfunctioned during an ignition cycle, the system will be "fail enabled" and the vehicle will start for all keys. In this case the code B2723 will remain set and be current for all keys.
7. If a new key must be tried, the key must have the proper mechanical cut and the VTD (Pass key III(R) module must "learn" the transponder value.
8. If only one key was available for the vehicle and the replacement key does not work, the VTD (Pass key III(R)) module must be malfunctioning.