A set of car keys inserted into a car door

What to do if your car immobiliser is faulty?

Immobilisers can be one of the best ways to keep your car safe from potential thievery, but what do you do if it’s not letting you, its owner, drive away? Scrap Car Comparison guides you through everything you need to know about immobilisers and what to do if they start playing up.

Immobiliser leaving your car immobile? Let Scrap Car Comparison offer you a way to get it out of your hands in a quick and easy manner. Simply call our friendly team today and see just how much your car could be worth as scrap or salvage. We only work with certified dealers , and there’s not a make of car we haven’t recycled in some way or another. With just one phone call to our experts, you’ll be given the best price in as little as 60 seconds.

Car keys in ignition of a car

What is a car immobiliser and what does it do?

An immobiliser is an electric safety feature in your car that prevents it from being started with the wrong key. An additional layer of security for you, it is one of the most common modifications on cars today and works in a way that stops potential thieves from being able to drive off by only allowing your car to start when it receives an electronic code from your key, and only your key.

Most modern car keys are fitted with a transponder that sends a code to the ECU (electric control unit) when you insert the key into the barrel. Some early immobilisers required you to press a button on the fob to deactivate them, or even a four-digit code, meaning there was just one code that unlocked your car. Today, there will be a different code each time you start the car, and they can even be activated by your phone with modern technology and keyless starting allowing your smartphone to also be your car keys. With smartphones also being payment cards now, the old “keys, wallet, phone” checklist can now simply be reduced down to “phone”.

How do I know if my immobiliser is faulty?

The most common sign of a faulty immobiliser would be difficulty locking or unlocking your car doors, as the fob will not be able to send the correct codes to the car to be able to open your doors. For the same reason, you may find difficulty starting your car – of course there could be other mechanical issues stopping this from happening which you should also explore, but you cannot rule out the possibility of a problem with your immobiliser. You may also find that your car alarm is not working correctly, or, one of the biggest telltale signs of immobiliser failure is a warning light on the dashboard.

What causes an immobiliser to fail?

Almost all immobiliser failures will be connected to issues with the codes going to and from your key fob and ECU. Quite often, these will be as the result of the wiring within your key fob malfunctioning or simply corroding as they age. Alternatively there could be an issue with the ECU itself, which may be an even bigger fix.

Can a low car battery affect the immobiliser?

A low battery in your car itself shouldn’t have an impact on the performance of your immobiliser, but of course there can always be unexpected issues if you’ve allowed your battery to run particularly low – or you’re having issues charging it, which could be an alternator problem. However, a low battery in your car’s key fob can have a big impact on the immobiliser, and should be one of the first things you check if you’re experiencing immobiliser-based headaches.

How much does it cost to fix a car immobiliser?

As with all mechanical problems, there isn’t a catch-all figure we can give you to say “this is how much it should cost” as this will depend entirely on the car that you’re taking into the garage. Even then, there are a lot more variables to take into account, such as if there are any peripheral problems being caused by or even causing your current problems. For example, you could need to replace the immobiliser as a whole, or you may just need to change the battery or transponder chip in your key fob. Or, if you’re very unlucky, it could be an ECU problem with larger repercussions. However, on average, the cost of an immobiliser repair will likely fall around the £100 mark.

Will a faulty immobiliser prevent your car from starting?

There is a very strong possibility that your car could have difficulties starting if you’ve got a faulty immobiliser. If your car doesn’t recognise the key that is being used to start it, it won’t be very happy and will not allow you to set off until it receives the correct code.

If your car’s immobiliser is playing up and you’re unable to get going again, then Scrap Car Comparison is here to give you a way out. We’ll scour the market to get the best price in your area, and with collection agents operating in 99% of all UK postcodes, we’ll even arrange a collection, absolutely free of charge. Get started today and see just how much your car could be worth as scrap in as little as sixty seconds.

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