What makes the lock go up and down when you press car key?

The lock goes up and down when you press the car key because of a mechanism called the door lock solenoid. This solenoid is a small, electromagnetic device that is located in the door of your car. When you press the car key, the solenoid is activated and it pulls a cable or rod that is attached to the door lock. This causes the door lock to move up or down, unlocking or locking the door.

The door lock solenoid is powered by the car's battery. When you press the car key, the electrical current from the battery flows through the solenoid and creates a magnetic field. This magnetic field attracts an armature, which is a metal plunger inside the solenoid. The armature is then pulled towards the solenoid, which moves the cable or rod that is attached to the door lock.

The door lock solenoid is a very important part of your car's security system. It helps to protect your car from theft by making it more difficult for someone to break in.