Remote keyless system
Encyclopedia
Keypad
A keypad is a set of buttons arranged in a block or "pad" which usually bear digits, symbols and usually a complete set of alphabetical letters. If it mostly contains numbers then it can also be called a numeric keypad...
s that are located on or near the driver side door. By entering the correct, pre-determined numeric code, one can gain access to a vehicle without a key - hence the phrase "keyless entry"; entry without a key.
In the case of automobiles an RKS performs the functions of a standard car key
Key (lock)
A key is an instrument that is used to operate a lock. A typical key consists of two parts: the blade, which slides into the keyway of the lock and distinguishes between different keys, and the bow, which is left protruding so that torque can be applied by the user. The blade is usually intended to...
without physical contact; power door locks
Power door locks
Power door locks allow the driver or front passenger to simultaneously lock or unlock all the doors of an automobile or truck, by pressing a button or flipping a switch....
can be locked or unlocked from several feet away or even from inside a building. (In this regard, the term "keyless" is a misnomer since the fob acts as an electronic key. Locking it in the car is just as much of a problem as doing the same with a mechanical key.)
A remote keyless system can include both a remote keyless entry system (RKE) and a remote keyless ignition system (RKI).
Remote keyless systems first began appearing as an option on several American Motors
American Motors
American Motors Corporation was an American automobile company formed by the 1954 merger of Nash-Kelvinator Corporation and Hudson Motor Car Company. At the time, it was the largest corporate merger in U.S. history.George W...
vehicles in 1983, including the Renault Alliance
Renault Alliance
The Renault Alliance is a subcompact automobile manufactured and marketed in North America by American Motors Corporation , with 623,573 examples manufactured for model years 1983-1987, and with a three and five-door hatchback variant, the Renault Encore marketed beginning in 1984.The two models...
. The feature gained its first widespread availability on General Motors
General Motors
General Motors Company , commonly known as GM, formerly incorporated as General Motors Corporation, is an American multinational automotive corporation headquartered in Detroit, Michigan and the world's second-largest automaker in 2010...
' W-platform vehicles
GM W platform
The W-body is an automobile platform from General Motors which underpins mid-size cars with front-wheel drive. The platform, originally code named GM10, began in 1982 under Chairman Roger B. Smith and debuted in 1988 with the Pontiac Grand Prix, the Buick Regal, and the Oldsmobile Cutlass Supreme...
(the Buick Regal
Buick Regal
The Buick Regal is a mid-size car introduced by General Motors for the 1973 model year. North American production ended in 2004 and began again in 2011. For the 2011 model year, Buick re-introduced the Regal to the North American market, positioned as an upscale sport sedan...
, Oldsmobile Cutlass Supreme
Oldsmobile Cutlass Supreme
The Oldsmobile Cutlass Supreme was a mid-size car produced by General Motors for the American market. It was always at the top of the Cutlass range. It began as a trim package, developed its own roofline, and eventually was mechanically divorced from the later, smaller Cutlasses.The Cutlass Supreme...
and Pontiac Grand Prix
Pontiac Grand Prix
Picking up where the Pontiac Ventura model left off, the Grand Prix first appeared in the Pontiac line for 1962. It was essentially a standard Pontiac Catalina coupe with minimal outside chrome trim and a sportier interior...
) in 1989.
Function
Remote keyless systems operate by broadcasting radio wavesRadio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
on a particular frequency. Most RKEs work at 315 MHz for some North America made cars and at 433.92 MHz for European, Japanese and Asian cars. Modern systems implement encryption
Encryption
In cryptography, encryption is the process of transforming information using an algorithm to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. The result of the process is encrypted information...
to prevent car thieves from intercepting and spoofing
Spoofing attack
In the context of network security, a spoofing attack is a situation in which one person or program successfully masquerades as another by falsifying data and thereby gaining an illegitimate advantage.- Spoofing and TCP/IP :...
the signal.
The system signals that it has either locked or unlocked the car usually through some fairly discreet combination of flashing vehicle lamps, a distinctive sound other than the horn, or some usage of the horn itself. A typical setup on cars is to have the horn or other sound chirp twice to signify that the car has been unlocked, and chirp once to indicate the car has been locked. Toyota, Scion, and Lexus use a chirp system to signify the car being locked/unlocked. While 2 beeps means that driver's door is unlocked, 4 beeps means all doors are unlocked. One long beep is for the trunk or power tailgate. One short beep signifies that the car is locked and alarm is set. Ford and Lincoln have the horn honk once to signify that the car is locked and alarm set.
The functions of a remote keyless entry system are contained on a key fob or built into the ignition
Ignition system
An ignition system is a system for igniting a fuel-air mixture. Ignition systems are well known in the field of internal combustion engines such as those used in petrol engines used to power the majority of motor vehicles, but they are also used in many other applications such as in oil-fired and...
key handle itself. Buttons are dedicated to locking or unlocking the doors and opening the trunk (or, on sport utility vehicle
Sport utility vehicle
A sport utility vehicle is a generic marketing term for a vehicle similar to a station wagon, but built on a light-truck chassis. It is usually equipped with four-wheel drive for on- or off-road ability, and with some pretension or ability to be used as an off-road vehicle. Not all four-wheel...
s and station wagon
Station wagon
A station wagon is a body style variant of a sedan/saloon with its roof extended rearward over a shared passenger/cargo volume with access at the back via a third or fifth door , instead of a trunk lid...
s, unlock/open the rear tailgate). On some minivans, the power sliding doors can be opened/closed remotely. Some cars will also close any open windows
Power window
Power windows or electric windows as well as electric or power window lifts are automobile windows which can be raised and lowered by depressing a button or switch, as opposed to using a hand-turned crank handle.- History :Packard introduced the first power windows in the 1940 Packard...
and roof when remotely locking the car. Some remote keyless fobs also feature a red panic button
Panic button
A panic alarm is an electronic device designed to assist in alerting somebody in emergency situations where a threat to persons or property exists....
which activates the car alarm
Car alarm
A car alarm is an electronic device installed in a vehicle in an attempt to discourage theft of the vehicle itself, its contents, or both. Car alarms work by emitting high-volume sound when the conditions necessary for triggering are met, as well as by flashing some of the vehicle's...
as a standard feature.
Some cars' engines with remote keyless ignition systems can be started by the push of a button on the key fob.
For offices, or residences, the system can also be coupled with the security system, garage door opener or remotely activated lighting devices.
Range testing
Programming
Remote keyless entry fobsSecurity token
A security token may be a physical device that an authorized user of computer services is given to ease authentication...
emit a radio frequency
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
with a designated, distinct digital identity code. In as much as "programming" fobs is a proprietary technical process, it is typically performed by the automobile manufacturer. (In point of fact it is a computer in the car which is programmed in the process, not the fob itself.) In general, the procedure is to put the car computer in 'programming mode'. This usually entails engaging the power in the car several times while holding a button or lever. It may also include opening doors, or removing fuses
Fuse (automotive)
Automotive fuses are a class of fuses used to protect the wiring and electrical equipment for vehicles. They are generally rated for circuits no higher than 24 volts direct current, but some types are rated for 42-volt electrical systems...
. The procedure varies amongst various makes, models, and years. Once in 'programming mode' one or more of the fob buttons is depressed to send the digital identity code to the car's onboard computer. The computer saves the code and the car is then taken out of 'programming mode'.
As RKS fobs have become more prevalent in the automobile industry a secondary market of unprogrammed devices have sprung up. Some web sites sell steps to program fobs for individual models of cars as well as accessory kits to remotely activate other car devices.
Trunk release
On cars where the trunk release is electronically operated, it can be triggered to open by a button on the remote. Conventionally, the trunk springs open with the help of hydraulic strutHydraulic cylinder
A Hydraulic cylinder is a mechanical actuator that is used to give a unidirectional force through a unidirectional stroke. It has many applications, notably in engineering vehicles.- Operation :...
s or torsion spring
Torsion spring
A torsion spring is a spring that works by torsion or twisting; that is, a flexible elastic object that stores mechanical energy when it is twisted. The amount of force it exerts is proportional to the amount it is twisted. There are two types...
s, and thereafter must be lowered manually. Premium models, such as SUVs with tailgates, may have a motorized assist that can both open and close the tailgate for easy access and remote operation.
Advanced Key
Some cars have a proximity system that is triggered if a keylike transducerTransducer
A transducer is a device that converts one type of energy to another. Energy types include electrical, mechanical, electromagnetic , chemical, acoustic or thermal energy. While the term transducer commonly implies the use of a sensor/detector, any device which converts energy can be considered a...
(Advanced Key
Advanced Key
Smart key is an electronic access and authorization system which is available as an option or standard in several cars. It was first used by Mercedes-Benz in 1998.-How it works:...
) is within a certain distance of the car. Sometimes called hands-free, one of the earliest systems was found on the 1993 Chevrolet Corvette (called the Passive Keyless Entry System). Today, this system is commonly found on imported vehicles, such as Infiniti, Mitsubishi, Mercedes-Benz, Audi, Subaru, BMW, Toyota, Volvo, Lexus, Nissan and Hyundai.
With the Advanced Key system, a vehicle can be unlocked without the driver needing to physically push a button on the key fob to lock or unlock the car and is also able to start or stop the ignition without physically having to insert the key and turning the ignition. Instead, as you approach the vehicle, the vehicle senses that the key (located in a pocket, purse, etc.) is approaching the vehicle. When inside the car's required distance there are two methods typically used by auto manufacturers to unlock the doors:
- Method 1 — Once the keyholder is in the car's "bubble" (the required distance from the vehicle for the key to be recognized) the car will automatically unlock the driver's door.
- Method 2 — Once inside the car's "bubble" the car doesn't unlock the door unless the keyholder touches one of the sensors located behind the door handles. As others attempt to get in, the system senses that the driver is within the "bubble" and as they touch the sensors behind their door handles, the car will unlock their door.
In certain vehicles, there are also various functions built into the transmitter to perform various tasks. For instance, pressing the unlock button twice and keeping the button depressed on the second push allows the keyholder to roll down certain pre-programmed windows and/or the sunroof. Other functions range from turning on the headlights and various electronic equipment (factory or aftermarket). On some Toyota, Nissan and Hyundai vehicles, the system prevents the driver or passenger from accidentally locking the keys in the car, via the sensor that detects whether the keyholder is within the "bubble" area outside the vehicle.