What Is Immobilizer: How Reliable is it for Your Car’s Security?

• Samiullah Sharief


• 5 Oct 2016

An immobilizer is an anti-theft device, which is found in most modern cars. As a matter of fact, in countries like Germany and UK, an immobilizer is mandatory in all cars. This device prevents thieves from hot wiring the car. An immobilizer works automatically and doesn’t need the owner of the car to activate it. Immobilizers are considered to be effective anti-theft devices.

How does an immobilizer work?

An immobilizer disables one of the systems which start a car’s engine. It usually disables the fuel supply or the ignition. There are two components involved; the transponder in the ignition key and a radio frequency reader. The radio frequency reader is found in the steering column. When the ignition key is placed, the transponder sends a unique identification code to the frequency reader. If the code is correct, the car’s computer control allows the ignition system or fuel system to start the car. If the code is incorrect or not present, the computer control disables the ignition or fuel system of the car and it will be unable to start unless the right key is used.

The most common way a thief steels a car is by hot wiring it. Hot wiring involves breaking the steering column and connecting the ignition wires of the car. With the immobilizer, the car won’t start even if the wires are connected, because the system deactivates the ignition. Immobilizers are very effective and have become a standard in most new cars. They can be installed on older cars as well.

How good is it for your car?

An advantage of the immobilizer is that it doesn’t need to be activated by the car owner. It works automatically and the car’s computer control detects any wrong code and absence of a key. However, immobilizers have some vulnerabilities. Many immobilizers in cars use the Megamos-chip, which can be crack-able. It’s faster to program a new key than to try to duplicate an existing key, especially in modern cars.

Immobilizer is a very important device and it’s mandatory for a car to have an immobilizer in many European countries. In a recent study, immobilizers have reduced the overall rate of car theft worldwide. According to the study, car theft has been reduce by 40% between 1995 and 2008.