Car Key Technology Explained
There are typically 2 elements to vehicle security - Vehicle entry and Starting the
It's rare to have to insert a key into your vehicle these days to open the doors, as most vehicles have push
button remote locking/unlocking.
Early remote systems used basic RF (radio frequency) systems which were not very secure - the signals could
be captured by a third party using black electronics and then played back to gain access to the vehicle. Newer
systems use a rolling code (or hopping) system. With this system the code transmitted is never the same, so
recording the signal is useless to a thief. A new code is generated constantly by the remote key. The vehicle's
receiver also generates the same new code as both items use the same key number for generating the next code, so
the receiver will always know what code to expect.
Ok...so what if someone presses the remote out of distance from the vehicle, surely the codes will be out of
sequence and the vehicle won't open, right? No. To counter this problem the receiver will accept the next 100 or
more rolling codes generated. As the code system normally has a billion to a trillion plus permutations, allowing a
few hundred variations does not compromise security.
However, if someone has been pressing the remote numerous times out of distance of the vehicle (maybe a hyper
bored sales rep or kids messing around!) then the remote may stop working and fail to open the vehicle. In this
case the remote can normally be sychronised again quite easily, depending on the vehicle - see our remote programming instructions.
Some manufacturers, particularly French companies like Renault and Peugeot employed infra red technology in some
of their early remote locking systems. This required pointing towards the vehicle at the receiver to lock and
unlock the vehicle. Most if not all infra red systems have been replaced by RF technology now. If you've lost a
remote control for an infra-red system there's a good chance you can easily reprogram a new or even second hand key
remote to your vehicle with our instructions.
Pioneering technology doesn't even require pressing anything for entry. Systems range from simply having the
key/smart card within a certain distance of the vehicle to open or lock the doors to fingerprint recognition
incorporated within the door handle.
Starting a vehicle
The original vehicle keys were no more advanced than a standard front door key to your house. While your house
can't be driven away your car can and ignition barrel locks on vehicle's have proved to be little defence to
With vehicles now being controlled by computers (ECU) this technology has also extended to the vehicle's key.
Most vehicles today now employ transponder technology in the key as added security - read here
On luxury vehicles keys can be individually coded to suit the driver. So once the key is inserted all settings
such as seat position, steering wheel height, headrest and door mirrors will adjust as programmed for that
There are even valet keys which only allow access to driving the vehicle but no access to the boot or glovebox
where valuables may be stored and will also restrict the vehicle's power output to avoid any abuse to the
The latest technology being employed by manufacturers like Mercedes Benz is to remove the key altogether
replacing it with fingerprint recognition.