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Engine Immobilizer – What Is It, And Is It Right For You?


You park your car in the employee parking lot at your job, and go inside. Immediately after you’re out of sight, a thief makes their way to your vehicle, reaching through a window you forgot to close to unlock your door. The thief  quickly hotwires your car, and starts up the engine. This whole process takes about 30 seconds. When you return with your cart full of groceries, your car has vanished.

Protect Your Vehicle

The situation described above is more common than you might think. Many owners of vehicles without alarm systems aren’t concerned about the security of their vehicle. This is especially true of owners of older cars, who may think, “No one would want to steal this old car!”. A thief may use your car while escaping from police officers, strip it down to sell as parts, or use it as a getaway car in a robbery. Even if you are able to recover your vehicle eventually, it may be damaged beyond repair. In order to help prevent this from happening, many people are turning to “engine immobilizers” to prevent their cars from being stolen.

What Is An Engine Immobilizer?

An engine immobilizer is a device which prevents the starter from activating unless a special microchip is within range. Some engine immobilizing devices require the microchip to be inside a key inserted in the ignition, while others simply need it to be within a certain radius. In most cases, the microchip is embedded inside the key or a device on the keychain.

How Does It Work?

An engine immobilizer consists of several devices that work together to operate correctly. Inside the key, a microchip emits a signal which is activated by an electromagnetic field. The key transmits a binary code that is unique, which can then be read by the car’s ECU (Engine Control Unit). If the signal is a correct match, the ECU will permit fuel to flow, and the engine to start up. If the car is attempted to be started with a key without a microchip, or if it is “hot-wired”, the engine won’t turn on.

Immobilizer Add-On Units

Even if your vehicle doesn’t have an engine immobilizer, you can purchase an add-on unit. Installing an engine immobilizer will often make you eligible for an insurance credit and/or discount, if you purchase the correct model. For a self-arming immobilizer, an insurance approved unit will intercept at least two circuits (usually the fuel pump circuit and the low-voltage ignition circuit). It’s best if you contact your insurance company to obtain a list of approved engine immobilizers.

Should I Get An Engine Immobilizer?

The easy answer to this question is yes, since an engine immobilizer is a great way to protect your vehicle from being stolen. However, there are several things you need to consider. Since the micro-chipped key you will be using to start your car is unique, it can be very expensive to replace. Some of these keys can cost from $300 – $800 to replace, depending on the system installed in your car. In addition to this, if the microchip becomes damaged, you will not be able to start your car (though some systems have safeguards to prevent this from happening). If your car doesn’t have an immobilizer installed, there is also the cost of the unit to consider – usually from $100 – $500. Essentially, the choice to purchase an engine immobilizer depends on the model of your car, your budget and the existing security features in your vehicle.