A proximity key is a small fob that allows for a keyless entry and ignition system. The fob communicates via radio waves with your car to lock and unlock doors and start the engine when within the acceptable range. Mercedes-Benz was the first to introduce this system back in 1998. Proximity keys are known by a variety of names. Some of the more common names are listed below:
The smart key allows the driver to keep the key fob in a pocket or purse when unlocking, locking and starting the vehicle. The key is identified via one of several antennae in the car’s bodywork and a radio pulse generator in the key housing. Vehicles with a smart key system also have a mechanical key back-up, usually in the form of a spare key blade supplied with the vehicle. Generally, the key hole is hidden behind a cover plate for aesthetics.
Vehicles with a smart key system can disengage the immobilizer and activate the ignition without inserting a key in the ignition, provided that the driver has the key inside the car. On most vehicles, this is done by pressing a starter button or twisting an ignition switch. There are also vehicles which have an ignition slot for the proximity key.
Many people don’t realize that their proximity keys contain an emergency key blade within the remote that may be used to open, close, and start your car. This back-up option is necessary in the event that the battery Smart key becomes depleted. Some vehicle can be started by the use of a transponder chip inside the Smart key that does not need batteries to work. There is usually a designated slot or area in which the key must be held in order for the transponder to be detected and start the engine.