What is keyless entry?

Doors that open with the brush of a hand, bootlids that lift with a wave of your foot: welcome to keyless entry

BuyaCar team
Jun 30, 2021

Sick and tired of that frustrating search for keys that have somehow tucked themselves away in the deepest and darkest corners of a rucksack or handbag every time you approach the car? A car with keyless entry is exactly what you need.

Keyless entry is a clever system that eradicates the need for a physical key to unlock car doors. All you need is for the fob to be somewhere about your person, whether that's in a pocket or in your bag, and the car will sense you're close and unlock the doors for you. It’ll lock the car as you walk away, too. No more searching for keys, and no more balancing shopping or children on your leg while you try and fish the key out of the bottom of your pocket.

This kind of tech is becoming increasingly common on cars of all shapes, sizes and price points, so if you're looking for the next step up in convenience, a car with keyless entry should be right up your street.

How does keyless entry work?

Keyless fobs contain identity chips that are constantly listening out for radio signals broadcast by their car. The radio signals can only travel short distances - typically less than five metres.

When you put your hand on the door handle of a keyless car (in some cases you have to press a button), the car sends out the short radio signal. If the fob is in range, it's then triggered to respond to the car, sending out its own code. The car recognises this and unlocks the doors.

The process is similar when it comes to starting the car, with a button to press to fire up the engine, with the systems usually being advanced enough that they will only start the car if the key fob is inside.

Increasingly, there are keyless boot opening systems, like the one on the BMW 5 Series below, with sensors on the back bumper. Waggle your foot underneath the bumper and the boot will open automatically, without you having to touch the handle - useful if your hands are full.

Now, there are even some cars that store a version of your key on your phone, so you can unlock the car without even having a physical key on you. Some BMWs, Teslas and the Ford Mustang Mach-E offer this capability.

What are the problems with keyless entry?

Your car doesn't automatically switch off the engine and lock itself if the fob goes out of range. This is to ensure that you're not suddenly stranded in the middle of the motorway if its battery dies. Keyless cars may also go through key fob batteries quickly, too.

However, this also means that you could drop someone off who has the key fob in their bag or pocket and then drive away. As soon as you turn the engine off, you won't be able to start the car again. And in most cases you still need to have a physical key fob and somewhere to put it, so your keys could clutter up a cupholder or jangle in the glovebox.

There are also serious concerns about the security of keyless entry systems, with a number of ways that thieves are able to breach them. In 2011, researchers from Zurich showed how the radio signals emitted by cars could be boosted, tricking it into thinking the key fob was nearby. Police have investigated criminals who block the signals from keyless devices, so that car doors never lock, and there are also allegations that thieves can intercept the codes that are transmitted between key fob and car.

In 2014, after a spate of Range Rover thefts, police advised owners to fit a steering wheel lock as a second line of defence against thieves who were able to overcome keyless security. Land Rover subsequently issued a fix for their cars.

Security experts recommend that you keep keyless entry keys away from doors and windows, and in a shielded protection case, as thieves can steal the signal to replicate your key wirelessly, from outside of your house. The most popular protective cases are called Faraday pouches, and can be picked up from auto parts stores for under £10.

Some manufacturers are now including technology that should prevent keyless car theft, such as a ‘sleep’ mode that prevents the key’s signal being transmitted if it’s not used for a few minutes. But it’s still worth taking your own precautions if you have a car with keyless entry, even if it’s just for your own peace of mind.


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