what is an immobilizer?

immobilizers are safety devices designed to prevent a car from being started by anyone other than the authorized user. They work by recognizing an electronic code linked to the ignition key of a vehicle, and disabling the engine if the wrong key is used. Immobilizers were one of the first major improvements in automotive security, and are now a common feature on most cars on the road today.

An immobilizer works in two stages. First, it reads data transmitted by an embedded chip inside of each ignition key, which contains a unique code assigned to each vehicle as part of its anti-theft system. If a key without this code is inserted into the ignition, the car won't start.

The second stage is an engine-control unit (ECU) or immobilizer module, which is installed in the vehicle's wiring system, connected to both the ignition switch and starter motor. It monitors signals from the key's embedded chip, then shuts down power to the starter motor if it receives a key without a valid code. The car must then be restarted with either a new authentic key (or duplicate) or with a special device called an override switch or transponder bypass module that contains all immobilizer codes.

One of biggest benefits of immobilizers is that they make it difficult for thieves to steal vehicles—only those with access to sophisticated tools can bypass them. Because they are automated security systems that always remain active, they provide additional protection and always remain visible as an additional layer of protection against theft. They can also help reduce insurance premiums due to their deterrent effects on attempted car thefts and track down stolen vehicles when found.