Car Security – Power Door Locks Explained

Knowing how power door locks work (considering that there are four to five different ways of unlocking a car) allows car owners to understand their car more.

A computer inside the car, called body controller, monitors and respond to all the possible ways to unlock the car door, including radio frequency and digital codes.

Once an action to unlock a door is made, either manually or through a key fob, the body controller commands the door lock actuator (think of a small motor with a hook) which then moves the latch up, making it possible to open the door.

“This system is quite simple. A small electric motor turns a series of spur gears that serve as a gear reduction. The last gear drives a rack-and-pinion gear set that is connected to the actuator rod. The rack converts the rotational motion of the motor into the linear motion needed to move the lock.

One interesting thing about this mechanism is that while the motor can turn the gears and move the latch, if you move the latch it will not turn the motor. This is accomplished by a neat centrifugal clutch that is connected to the gear and engaged by the motor.

When the motor spins the gear, the clutch swings out and locks the small metal gear to the larger plastic gear, allowing the motor to drive the door latch. If you move the door latch yourself, all of the gears will turn except for the plastic gear with the clutch on it.”


  • The different ways to unlock a car door are using an actual key or a combination lock, pulling the knob from the inside of the car, or sending a signal from a control center.
  • If you get locked out of your car, a locksmith that comes to your aid will use a thin metal strip with a flat hook to open the door.

It takes an expert to solve your car lock problems, and it takes a reliable company to come to your aid at any place and time the emergency happens.

We at Value Locksmith will come quickly, solve your problem easily, and set you on your way in no time. Call us now at 1-877-399-8882 or save our number.

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