Due to the presence of this safety device, if you drop the keys on the ground the car may not start anymore! Let’s see how the immobilizer works and what it is.

Electronic immobilizer: what it is

The immobilizer or immobilizer is an anti-theft device that can be mechanical or electronic. The latest models produced by car manufacturers are electronic because they are more difficult to circumvent.

The vehicle immobilization system prevents the engine from starting when it does not recognize its actual ignition key. It is thanks to the immobilizer that thieves today cannot steal cars simply by “connecting the wires” under the steering wheel.

Electronic immobilizer: how it works

Operation is rather complex: the immobilizer checks the vehicle’s electrical power systems and allows it to be started only if the system is able to recognize the key code.

The system can be compared to the classic password for turning on a smartphone. The immobilizer must receive a code that must be transmitted correctly by the remote control (or by the ignition / opening key). The starting key code is transmitted via a transponder. If the code does not correspond the electronic immobilizer is not deactivated and the vehicle cannot be put into operation.

FIAT electronic immobilizer

The vehicle immobilizer is the most widespread anti-theft system in the automotive sector. It is found, as standard, on all cars, now also in the entry models of economical cars like the Fiat Panda or the Fiat 500.

If it is true that the immobilizers prevent the theft of the car by connecting the wires, it is also true that the more organized thieves are able to decode it and reset it.

Resetting the electronic immobilizer is not difficult, so much so that especially for the Fiat manufacturer, on the web there is no lack of guidance on how to eliminate or scodificare the Fiat immobilizer. The guides are not born to help aspiring thefts but because sometimes this device has given problems, especially on the old Fiat Punto models.

engine immobilizerBMW electronic immobilizer

The BMW electronic anti-start system takes the acronym of EWS. As explained, the immobilizer encodes and decodes the vehicle access and the engine starting via the ignition key.

How does the BMW electronic immobilizer work? Unlike the a car immobilizer Ford, Fiat, Lancia, the BMW immobilizer starts a two-way dialogue with the car’s ECU because it has two access codes. In simple words:

In the ignition key there is a chip in which a fixed code is stored and a variable code that changes with each ignition.

Activating the ignition of the car, the immobilizer first recognizes the fixed code and then requests the variable one. If both passwords are correct, the on-board electronics “unlocks the engine” and allows it to start.

Data transmission is via an antenna integrated in the steering lock and the key with integrated remote control.

Ford electronic immobilizer

As with the Fiat immobilizer, the Ford electronic immobilizer was often the cause of sudden blockages and error signals. Not a few users have found themselves dealing with the error message “Immobilizer Fault, urgently repairing”. In this case the only possibility you have is to contact the dealer directly or at a mechanical workshop specialized in the duplicate car key practice.

Like the other immobilizers, the Mercedes electronic immobilizer is also activated by removing the key from the ignition lock and deactivating it by switching on the ignition.