Power door locks (also known as electric door locks or central locking) allow the driver or front passenger to simultaneously lock or unlock all the doors of an

automobile A car or automobile is a motor vehicle with wheels. Most definitions of ''cars'' say that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people instead of goods. The year 1886 is regarded ...

truck A truck or lorry is a motor vehicle designed to transport cargo, carry specialized payloads, or perform other utilitarian work. Trucks vary greatly in size, power, and configuration, but the vast majority feature body-on-frame constructi ...

, by pressing a button or flipping a

switch In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type of ...

. Power door locks were introduced on the luxury Scripps-Booth in 1914, but were not common on luxury cars until

Packard Packard or Packard Motor Car Company was an American luxury automobile company located in Detroit, Michigan. The first Packard automobiles were produced in 1899, and the last Packards were built in South Bend, Indiana in 1958. One of the "Th ...

reintroduced them in 1956. Nearly every car model today offers this feature as at least optional equipment. Early systems locked and unlocked only the

car doors A car or automobile is a motor vehicle with wheels. Most definitions of ''cars'' say that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people instead of goods. The year 1886 is regarded as t ...

. Many cars today also feature systems which can unlock such things as the luggage compartment or

fuel filler cap A fuel tank (also called a petrol tank or gas tank) is a safe container for flammable fluids. Though any storage tank for fuel may be so called, the term is typically applied to part of an engine system in which the fuel is stored and propelled ...

door. It is also common on modern cars for the locks to activate automatically when the car is put into gear or reaches a certain speed.

Remote and handsfree

In 1980,

Ford Motor Company Ford Motor Company (commonly known as Ford) is an American multinational automobile manufacturer headquartered in Dearborn, Michigan, United States. It was founded by Henry Ford and incorporated on June 16, 1903. The company sells automobi ...

introduced an external keypad-type

keyless entry system A remote keyless system (RKS), also known as keyless entry or remote central locking, is an electronic lock that controls access to a building or vehicle by using an electronic remote control (activated by a handheld device or automatically b ...

, wherein the driver entered a numeric combination —either pre-programmed at the factory or one programmed by the owner— to unlock the car without the key. Early- to mid-1980s

Nissan Maxima The Nissan Maxima is a full-size car manufactured and marketed by Nissan and offered as Nissan's flagship sedan primarily in North America, the Middle East, and China — and currently in its eighth generation. Having debuted for model year ...

s could also be installed with a keypad, which would also retract the windows and moonroof once the car was successfully unlocked by pushing a specific button on the keypad. During the 1990s the

Subaru Legacy The is a mid-size car built by Japanese automobile manufacturer Subaru since 1989. The maker's flagship car, it is unique in its class for offering all-wheel drive as a standard feature, and Subaru's traditional boxer engine. The Legacy was sol ...

could also be opened by pulling the drivers external door handle a specific number of times to enter a passcode number that would unlock the driver's door only. Today, many cars with power door locks also have a radio frequency remote keyless system, which allows a person to press a button on a

remote control In electronics, a remote control (also known as a remote or clicker) is an electronic device used to operate another device from a distance, usually wirelessly. In consumer electronics, a remote control can be used to operate devices such ...

key fob, the first being available on the French made Renault Fuego in 1982. Currently, many luxury makers also allow the windows to be opened or closed by pressing and holding a button on the remote control key fob, or by inserting the ignition key and holding it in the lock or unlock position in the external driver's door lock. The remote locking system confirms successful locking and unlocking through either a light or a horn signal, and usually offers an option to switch easily between these two variants. Both provide almost the same functionality, though light signals are more discreet while horn signals might create a nuisance in residential neighborhoods and other busy parking areas (e.g. short-term parking lots). Some manufacturers offer the ability to adjust the horn signal volume. Other cars have a proximity system that is triggered if a keylike

transducer A transducer is a device that converts energy from one form to another. Usually a transducer converts a signal in one form of energy to a signal in another. Transducers are often employed at the boundaries of automation, measurement, and con ...

(

Advanced Key A smart key is an electronic access and authorization system that is available either as standard equipment, or as an option in several car designs. It was first developed by Siemens in 1995 and introduced by Mercedes-Benz under the name "Keyless ...

or handsfree) is within a certain

distance Distance is a numerical or occasionally qualitative measurement of how far apart objects or points are. In physics or everyday usage, distance may refer to a physical length or an estimation based on other criteria (e.g. "two counties over"). ...

of the car.

References

{{DEFAULTSORT:Power Door Locks Automotive accessories Automotive electrics Locks (security device) Vehicle security systems sv:Stöldskydd (bil)#Centrallås

Remote and handsfree

See also

References