11454 Reeder Road, Dallas, TX 75229 972-241-6326
11454 Reeder Road, Dallas, TX 75229 972-241-6326
  • Thief Trying to Steal Car

    Why is an Immobilizer Used in Cars?

    Posted on January 6, 2019 | By wpcars

    For many of us, our biggest fears as vehicle owners are somewhere between crashing, having mechanical issues of any kind, or having our vehicle broken into and perhaps having our vehicle stolen. Especially those of us that live in big cities or in high crime neighborhoods, we are looking for ways to protect ourselves and our vehicles. Beyond the use of car alarms and anti-theft sensors, many newer vehicles will also have immobilizers.

    Immobilizers do pretty much what it sounds like they do — they immobilize the vehicle to prevent another person from stealing your car and driving off with it without the key. With the implementation of immobilizers in most vehicles, motor vehicle thefts have decreased significantly.

    How Immobilizers Work

    Immobilizers are an electronic security system or device specially designed for the vehicle it is protecting. It prevents the engine from starting when the corresponding key (or token) is not within range and/or present. More often than not, this will only stop a vehicle theft if the thief is attempting to “hot wire” the vehicle. If they were able to obtain your key, then they will be able to start your car. However, many vehicles manufactured after 2007 (outside the United States as early as 1991), will usually be equipped with immobilizers, and even older vehicles can have add-on immobilizers installed.

    When immobilizers were invented, the operator or owner of the vehicle had to remember to start up the system so it would engage. These days, if you vehicle is equipped with an immobilizer, it is automatically engaged when the vehicle is turned off and locked. There is a microcircuit, or very small computer, inside the key (or token). This then broadcasts a unique binary code that can be read by the vehicle’s Engine Control Unit (ECU). When the ECU is able to determine that the coded key is current, valid, and present, the ECU is able to activate the vehicle’s engine.

    In some vehicles, attempts to use an unauthorised or fake key may cause the vehicle to refuse to start for a set period of time, and in some highly advanced systems, a security firm may be alerted that an unauthorised attempt was made to start the car. However, there are still some vulnerabilities when it comes to the use of immobilzers as anti-theft devices in vehicles. Since they use an electronic chip or transponder, they can be hacked when inside the vehicle and coded to a new key. This is difficult to do correctly, and is rarely attempted.

    Signs Your Immobilizer is Wearing Out

    In order for the immobilizer to continue to function as an anti-theft mechanism, all aspects need to be functioning properly. If you begin to experience issues with you car door not unlocking or you being unable to lock your car door, it could be a sign that your key fob is not properly registering with the immobilizer system. Your car alarm is also associated with the immobilizer system, so if your car alarm no longer engages, you more than likely also have a flaw in the immobilizer. If you are still able to lock and unlock your vehicle properly, but your engine doesn’t start and there are no other known issues that could be preventing the engine from running, it could potentially be associated with bad wiring in regards to the vehicles immobilizer.

    Car Immobilizer Anti-Theft System

    Ask the Professionals

    If you suspect issues with the immobilizer connection or faulty wiring, the immobilizer will need to be physically examined. If it appears to have damaged wires or faulty connections in the wiring, you will need to have the immobilizer replaced. If you are unsure if it is a faulty immobilizer or not, it is best to consult a professional to be sure that the issue is properly addressed, in case it is a more severe issue.

    Whether your car has an immobilizer or you need one installed, it is best to consult a knowledgeable professional in regards to the system and how it properly operates in regards to your specific vehicle. If you live in or around Dallas, Highland Park, University Park, Irving, or Coppell, TX, consider talking to Louden Motor Car Services, Inc. for any and all immobilizer questions and/or concerns.


Louden Motorcar Services, Inc.
11454 Reeder Road, Dallas, TX 75229

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