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System overview: General

Fig 1: Locating Immobilizer System Components
GLL142320Courtesy of VOLVO CARS OF NORTH AMERICA.

The immobilizer system increases the level of the vehicle safety system by making it extremely difficult to use the vehicle unless a valid key, which belongs to the vehicle, is used to start it. The identity of the key is checked when the vehicle is started, and if the key is not approved the engine will not start. The customer will not notice this function as long as a valid key is used an no fault occurs.

The immobilizer system includes:

Definitions: 

Activated system:  The system means that the vehicle cannot be started.

Deactivated system:  The key has been checked and approved. The system permits the car to start.