London Auto Locksmith

Key Technology

We specialise in chipped car keys. All cars built in the past 10 years use this transponder chip technology to prevent theft. It is a "passive immobilisation" system and relies on a tiny chip embedded in the plastic head of the car key. If everything is working correctly then you won't even know about it. However, when you switch off the ignition, the immobiliser comes on automatically. The next time you switch the ignition on, an aerial around the ignition sends out a pulse. This has enough energy to power up the chip, which sends back a pulse of its own.

The immobiliser checks the code contained in this radio signal and if it is correct, allows the engine to start. It is this inductive principle which allows the transponder key to function without a battery, and which makes the key's memory non-volatile. This is extremely useful if you want your car to start reliably time after time, but can lead to people being convinced that it is "just a normal key" as it didn't have a remote button or a power source. In almost all cases the remote operates independently of the immobiliser so that if your battery goes flat you can still start your car.

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Lost Car Keys


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