How does keyless entry work?
The electronic keys used by many car manufacturers today no longer rely on infrared (IR) signals to work.
Remote control units for home appliances such as televisions still use them.
The electronic keys used for keyless entry in cars uses radio signals.
These keys function as both receiver and transmitter.
Some cars with keyless entry systems require a miniature button on the door handle to be depressed in order to lock and unlock them.
Other models with keyless entry use a capacitive discharge switch on the handle instead.
Merely touching the handle commands the system to lock and unlock the doors and boot.
Touch activation is not new and has been used widely in elevators, for example.
How does keyless entry prevent drivers from locking the car with the key inside it?
The answer is that radio signal antennae “around” the car are configured to detect if the key is outside or inside the car.
If you inadvertently leave the key in the car, the antennae will pinpoint the key’s location as being inside the car.
The engine can also be started, but the door locks cannot function from outside the cabin.
Why is this keyless entry safety feature important?
This prevents someone from sneaking into your car while you are standing outside (perhaps to refuel or access the boot), starting the engine and driving off.
However, if the engine has not been turned off, the car can still be driven away even if the key is in your pocket.
It does not matter how far you are from your car.
Only a warning light and/or chime from the instrument panel tells you that the key is not detected.
But the car can be driven for as long as there is fuel and the engine is not shut off.
If it was technically possible to lock a car from the outside with the key left inside, it would mean that anyone could unlock it in the same way.
To prevent unauthorised access to your vehicle while you are behind the wheel, a keyless entry system is designed to also detect if the key is within the car’s cabin.
What if you’re locked out? Here’s how to get keys out of a locked car!