Push Button Start(Keyless Ignition Systems): How it Works.
Keyless ignition systems come with a fob that you can keep tucked away in your pocket, purse, briefcase, or anywhere in close proximity to the receiver inside the vehicle. The fob transmits a unique low-frequency signal to the car’s computer system, which then validates that the correct signal has been sent and allows you to push a button on the dashboard or console to start the engine. Shutting off the motor is just as hassle-free: Simply press the start/stop button. And, in addition to keyless ignition, most systems also include keyless entry, allowing you to enter the car without inserting a key or hitting a button on the fob.
Keyless ignition systems contain safeguards to ensure that your car doesn’t spring to life at the wrong time. Pre-start safety checks by the car’s computer ensure that the vehicle is in park and that your foot is on the brake before allowing the engine to start. For added insurance, some designs require you to flick or rotate a switch before pressing the start button. And in most cases, the key fob must be inside the vehicle in order to get the motor running.
Keyless ignition also makes it more difficult to lock your keys in the car or the trunk. For one thing, the fob can remain safe and snug in your pocket at all times. But some systems are smart enough not to allow the doors to lock if, for some reason, you leave the fob inside the vehicle or in the cargo area. Others send an audible alert if you attempt to shut a door or trunklid with the fob still inside.
These systems are designed to help deter break-ins and vehicle theft. Since the car’s computer will only recognize a signal from its own fob, thieves will have a harder time getting in and starting the engine. There’s no metal key that can be copied and no mechanical steering-column lock that can be forced or otherwise defeated.