How do modern Car Keys & Remote Control Fobs work?
MODERN CAR KEYS have changed dramatically in two decades – transforming from traditional metal door keys into high-tech security systems strong enough to protect a bank vault.
The shake-up has been a massive boon to lazy drivers – who can now unlock their car at the touch of a button. And the latest keyless entry systems already mean that drivers of some prestige vehicles can fire up the gas on their favourite sports car by simply sitting down inside.
It’s all sounds like a couch-potato Knight Rider high-tech heaven, and it is….until the technology grinds to a halt leaving you stranded locked-out of your vehicle.
That’s when the old days of slipping a Slim Jim coat hanger down between the window and the door panel don’t seem so bad after all.
What should you do when you are left standing around outside your car red-faced, desperately pushing a button that doesn’t work or wondering how to make to dog sick so it spits out your fob?
First, here are some Car Key basics. Few drivers know that most modern Car Keys are basically three keys in one.
First off, there is the basic metal blade everybody recognises which works just like a door key.
The second layer of protection is called an immobiliser chip. It’s a small glass chip concealed inside the plastic part of your key. By law, virtually every car made after 1995 has a chip embedded in all the keys somewhere. Most drivers don’t even know the chip is there…but it is – even on simple Car Keys with no buttons – and without it, you are going nowhere.
Imagine you broke off the plastic part of the key. You could still use the Key Blade to open the car door. You could also put the blade in the ignition and turn it…If you did that, you would here the engine rumble, but it WON’T fire into life.
Why? There’s a coil near the ignition barrel which is linked to the on-board computer which controls your car. Before allowing fuel to flow to the engine and the vehicle to fire up, the computer asks the coil to check that the correct chip is nearby. If it isn’t – you’re car might as well have four flat tyres. You are stuffed.
The third layer of optional protection is the remote control fob. We all know how this works; you push a button to lock and unlock the doors. If an alarm system is fitted, the buttons will probably disarm the alarm at the same time as unlocking the doors.
You can find out more details about the technology – and how to fix it when it goes wrong – by visiting the home page of this AutoKey Squad website. Don’t worry, there are alot of options that work out cheaper than visisting an expensive Car Dealership!
That’s it – It’s pretty simple. I’ll be addressing what to do when the system goes wrong in my next article.
By David Jackson, The AutoKey Squad London Lost Car Specialists

