How Power Door Locks Work

Here's how the power door locks and latch works on your car.
The door latch on a car door is responsible for keeping the door shut against the body of the car. For safety reasons, this door latch requires the movement of a handle attached through a connecting rod to open.
The door lock part of the mechanism essentially disables the connecting rods that attach to the interior and exterior handles respectively. It does this by forcing two tabs that would otherwise interlock and open the latch, out of each other's way so they miss each other when the door handle is opened, "locking" the door.
The power door lock part of the mechanism consists of a small 12V DC electric motor with a built in thermister. The thermister actuates when the door lock is overcycled to prevent it from wearing down the motor. The motor powers a small geartrain which turns a small arm. That arm moves the locking rod up and down, "locking" the door in the same fashion as manually locking it.
Most modern cars have built in electronics and sensors to sense the position of the lock and key. These switches essentially feed information to the body control unit to control things like window opening functions, alarm functions, and weather to unlock all doors if turned multiple times.
Finally, the key cylinder comprises of a toothed key that slots into a key cylinder. Inside, small tumblers on springs, conform to the shape of the key, allowing it to rotate in the barrel. These tumblers can be moved around for various key combinations, and is called "rekeying" the cylinder.
The door lock actuator in this video was taken off a 2001 Toyota Corolla.
Check out the speedkar99 Facebook page:
/ speedkar9
Check out the speedkar99 Linkedin page:
/ speedkar99
Follow speedkar9 on Instagram for behind the scenes coverage:
/ speedkar9
Subscribe for more videos just like this:
www.youtube.co...