How does keyless entry work? (for cars and trucks)
If you’ve bought a car within the last 10 years, you probably received a small remote with your vehicle. This remote usually has three buttons that allow you to open, lock, and open the trunk of your car. It may also have features like an alarm, a panic button, or remote start, especially in luxury cars.
Additionally, there are remote controls that allow you to start your engine without inserting a key into the ignition. Instead, you just hold the remote close by and press the engine start button, and your engine will start automatically.
This is because a receiver in the ignition switch receives the signal from the remote or keyless entry transmitter. Here’s how a keyless entry fob works.
Keychain Basics
A key fob is essentially a radio transmitter that sends a code to a radio receiver in your car. A controller chip inside the key fob generates a secure code before sending it to the receiver.
The more technical name for this code is a 40-bit rolling code. “40-bit” means that it generates a random code from a pool of roughly one trillion possible codes.
How does a car key fob work? Every time you press a button on the remote, the key fob sends this random 40-bit code and a short code to the car’s receiver. The 40-bit code is a security function, and the function code tells the car to perform a specific function such as: B. Open or close the door.
The receiver and sender are synchronized when generating the random number, so the receiver recognizes the secure code sent. Therefore, if someone tries to open or start your car with a key fob, it won’t work because the transmitter is not synchronized with your receiver. As a result, the receiver doesn’t recognize the number and it doesn’t perform any functions.
A key fob not only gives you keyless access to your car, it also mitigates the possibility of locking your keys inside the car. Many times, you may use your key fob to lock and unlock your doors. So, if you forget your keys in the car, your doors will remain unlocked.
However, in the unlikely event that you have locked your key fob in the trunk or car and it is out of reach, you will likely need to call your dealer to have it opened for you as they are the only ones who can make a new key fob.