How Many Keys Are Generally Provided When Buying a Car?

[IanAnn]

When buying a car, two keys are generally provided—one as a spare and the other for daily use. The primary function of car keys is to remotely lock and unlock the car doors. By holding down the lock button on the key, you can close the windows. Pressing the red horn-shaped button on the key helps locate the car, while pressing the trunk unlock button automatically pops open the trunk. Basic principle of car keys: A weak radio wave is emitted from the owner's vicinity, which is received by the car's antenna. The electronic control unit (ECU) then identifies the signal code, and the system's actuator performs the locking or unlocking operation. How to start the car if the key battery is dead: Each key contains an electromagnetic coil that emits microwaves. The push-to-start button also has an electromagnetic coil to receive these microwaves and relay them to the car's computer. The computer analyzes whether the key matches the vehicle—if it does, the car will start.