Immobilizer is an electronic security system that aims to prevent vehicle theft by controlling access to the engine. It works on the principle of authorization, which must be met in order to start the vehicle. Here is the general way an immobilizer works:

• Identification: when a vehicle owner inserts a key into the ignition or uses another form of identification, such as a proximity card, the immobilizer begins the identification process. Each key or proximity card is paired with a specific vehicle.
  

• Communication with the central control system: When a key is inserted or another form of identification is used, information is sent to the vehicle's central control system, which controls the immobilizer system.

• Authorization check: The central control system compares the information from the key or proximity card with the data in its memory. If the data match and the identification is correct, the immobilizer recognizes the user as authorized and allows the vehicle to start.