How do immobilizers work?

An approved immobilizer cuts power to the starter, the ignition and, in most cases, the fuel supply. The immobilizer can only be deactivated by a special transponder, which sends a signal to the immobilizer unit and allows the vehicle to start.

The immobilizer controls electricity to your vehicle's fuel system, ignition and starter. The transponder in your key or key fob signals the immobilizer to activate them.

In some approved immobilizers the transponder is imbedded right in the key. In others, it's located in a fob that hangs from your keychain.

Without the transponder, the immobilizer won’t allow power to flow to the starter, ignition and fuel supply. When someone tries to steal your car, it won’t start.

Approved immobilizers are the best protection against vehicle theft.

You may have heard that some vehicles with factory-installed and after-market immobilizers are being stolen. That’s because some immobilizers don’t meet all the requirements of the ULC S338 Canadian standard. These immobilizers may only disable two systems in a vehicle, or may not use a transponder-based security system.

By contrast, approved immobilizers disable three vehicle systems, use transponder technology, and can withstand prolonged attacks. When installed according to national standards, these immobilizers have not been defeated by auto thieves.