Eli5: How do keys like the mini cooper work


How do keys that aren’t really “keys” used to start the ignition work. Why cant i stick another person key in and it work? I feel maybe it works like card chip, but how does it maintain power by doing that?

In: 0

Are you talking about a key fob or smart key? Those usually have small button batteries in them that can power them for quite a long period of time, as they’re not constantly sending signals out. They’re only active when you press any of the buttons on them.

The fob has a chip in it similar how credit cards have embedded chips. The car will only respond to a fob with the correct chip, which has to be programmed into the car’s computer, usually by a dealer.

I assume you’re referring to [this key](https://cdn.shopify.com/s/files/1/1882/7779/products/minikey3_1024x1024.jpg)?

The answer is RFID, it sends out a code via a wireless signal that the car reads and knows its the right key, the signal strength let’s it know the key is in the “ignition” (not really an ignition switch, but I don’t know what they call it).

*Most* cars that use this also have rotating codes to prevent cloning, and any new key would have to be paired with the car to work, similar to how your phone knows which of an identical pair of Bluetooth devices to connect to.