These transmitters allow the vehicle's owner to send a command to the vehicle from several yards away, and the vehicle may flash its lights, sound its horn, open a door or start in response. The wireless radio transmitters work in similar way as the lower-powered transponders, except they use radio waves--coupled with a small, hidden radio antenna inside the car--to broadcast their signal over greater distances. Some auto manufacturers even use radio transmitters to replace physical keys altogether; these devices interact electronically with the vehicle's security system to identify the keyholder and allow the engine to begin by pressing a button rather than turning a key.
When the chief is inserted and turned, the composition of the vital allows it to press against the distinct pins and tumblers inside the locking mechanism and measure freely; a important with a contrary mannequin Testament not turn within the lock since steel keyguards prevent movement of keys that conclude not exactly align with the functional pins and tumblers.
Transponders
The feature that truly sets coded automotive keys except their mechanical cousins is a small transmitting device either visibly mounted somewhere on the key or embedded within the key body. This transponder--so named because it both transmits and responds--emits a weak electronic signal that can be picked up by electronic devices in the car's ignition system. If the transponder is not present, the electronic security devices prevent the car from starting even if the mechanical portion of the key aligns and turns properly. This security device can be highly effective at preventing auto theft, as the transponder is capable of generating millions of security codes that must be received and accepted by the vehicle's security system for ignition to occur.
Radio Transmitters
Radio transmitters are becoming increasingly common in coded automotive keys.
