What is an immobilizer system?

Answer 1

An immobilizer / immobilizer is an electronic device that is fitted to a vehicle to prevent the engine from running unless the correct or authorized user is present. It uses a Driver ID via walk-up or walk away Fob with RFID technology. It also prevents the vehicle from being hotwired after entry has been achieved. It is not a GPS system, but can be integrated with many GPS systems to offer enhanced features.

· Immobilizers became a mandatory requirement for any vehicles entering into Canada in September 2007 (Standard 114). Immobilizers have been mandatory in all new cars sold in Germany since January 1998, United Kingdom in October 1998, Finland in 1998, and Australia since 2001.

· Early models used a static code in the ignition key (or key fob) which was recognized by an RFID (Radio Frequency Identification) loop. If the code was unrecognized, the multi circuit immobilizer would disallow ignition to take place. Current models of immobilizers use rolling codes or advanced cryptography to defeat copying of codes.

Many newer vehicles are equipped with immobilizers at the factory. Several kinds of after-market immobilizers are also available. But not all immobilizers are created equal.

The transponder is a radio frequency chip located in the key or key fob. When the chip is near the ignition, it sends a signal that deactivates the immobilizer, allowing the vehicle to start. The vehicle will not start without that signal. That means that when you walk away from your vehicle with the key or key fob, the immobilizer is armed and your vehicle cannot be started.

Some immobilizers house the de-activation system in the steering wheel column. In addition, many iimmobilizers only disable one system in a vehicle, while best in class immobilizers must disable three.

Many factory installed immobilization systems are electronic and function in conjunction with the vehicle computer (PCM/ECM). The electronic and ignition only systems tend to be ineffective against professional car thieves. Best in class 3 circuit systems, when properly installed, act as an effective deterrent to theft.

Answer 2

There are a number of types of immobilizers for automotive use. Many new cars come with them installed from the factory, and in those cases the actual electronic control unit for the engine comes from the factory with an immobilizing circuit that will prevent the fuel pump and usually the ignition circuit as well from operating unless a transponder device is within the range of the sensor. These are the best type of immobilizer in terms of safety, because they are not a separate electrical circuit which can be easily tampered with like aftermarket systems.

Immobilizers have a radio frequency transmitter that goes on your keychain. The sensor that is in the dashboard or somewhere near the ignition detects the unique frequency of the transmitter in order to allow the car to run.

Aftermarket immobilizers come in all different styles. Generally speaking, it depends entirely on the specific cars specifications in terms of fuel delivery system and ignition system to determine how to immobilize the car.

For example, a car with an electronically powered fuel pump (which is likely fuel injected) can be easily immobilized if the power relay to the fuel pumps operation is intervened from the immobilizer system. A fuel injected car with an immobilizer circuit would typically disable the fuel pump, fuel injection control, as well as the ignition circuit. A car that is carbureted on the other hand, likely uses a mechanical fuel pump from stock, and therefore you cannot prevent fuel flow directly without the use of solenoids in between fuel lines to stop flow physically. A carbureted car with a mechanical fuel pump would likely only have the ignition circuit disabled in the event of immobilization.

A very simple immobilizer simply cuts power to the starter by replacing the starter relay with one that is controlled by the immobilizer control circuit if the key transmitter is not present. These systems are good, but nowhere near the theft prevention that a factory immobilizer provides. With enough time and thought, one could easily shop ahead of time for the specific relays a car they are looking to steal has, and replace the immobilizers aftermarket relays with the stock ones and cut the immobilizer circuit out of the equation.

Thieves however are usually looking for a quick joy ride, so the immobilizer is a great theft prevention device!

Answer 3

An immobilizer or immobilizer is an electronic device fitted to an automobile which prevents the engine from running unless the correct key (or other token) is present.