5.1 Immobilizer Operation

The immobilizer functionality is tested using the base station hardware (ATSAMC21-XPRO/ATA5291-XPRO or ATA5293-XPRO/LF antenna module or X-10013-002 antenna) and the ATAB5702A fob board. The CARS PC application displays the UID, challenge, response and result of the authentication in the Immobilizer Status window each time the authentication command is executed. Perform the following steps to test the immobilizer using the CARS PC application running on the host PC:

1. If not done so already, follow the procedure detailed in CARS Kit PC Evaluation Utility.
2. Navigate to View > Immobilizer. The Immobilizer Status window shows the following data fields:

   

   • “Immobilizer UID” – Displays the unique ID value received from the fob
   • “Immobilizer Challenge” – Displays the most current challenge data sent to the fob
   • “Immobilizer Response” – Displays the most current response data received from the fob
   • “Immobilizer Result” – Displays the authentication status
   • “Log file” – Selecting this check box creates a new record line in a Comma Separated Variable (CSV) document for each received message when it is selected
3. Place the fob near the LF antenna module or X-10013-002 antenna within a short distance (<10 cm).
4. Click the Read UID button to execute the ReadUID command. The ReadUID command is sent to the fob and the fob responds by sending its UID.
   Note: This command works even for fobs not learned by the system.
5. Click the Start Authentication button to execute fob authentication. The green shield icon () indicates the immobilizer status upon successful execution of the start authentication command.
   Note: The “Immobilizer Challenge” and the “Immobilizer Response” values are different each time a new authentication sequence is executed because the “Immobilizer Challenge” is a random number. The UID value is fixed every time.
6. To test passive operation, remove the battery from the fob and repeat steps 3 through 5.