Remote control keys and key fobs transmit a coded signal that is received by the vehicles theft deterrent module. If the code meets preset criteria, the module closes a switch that enables either the drivers’ door or all doors to be locked and unlocked as required.
Pressing the button a second time when locking some vehicle activates the dead lock actuators and deadlocks the vehicle.
For the remote key and computer to exchange information, wireless communication is needed. High frequency electromagnetic fields known as “Radio Frequency” or RF is used. This system relies upon the same basic technology as cell phones, TV and radio.
The remote fob can have one button to lock and unlock; 2 buttons, one to lock and the other to unlock; 3 buttons, where the third button activates the trunk or tailgate; or 4 buttons, where the fourth activates a panic alarm, locking the doors, sounding the horn and flashing the headlights and hazard lights.
Some vehicles actively transmit a radio code looking for a specific key. As the driver approaches the vehicle, the vehicle locates the key and the theft deterrent module unlocks the vehicle. When the driver leaves the vehicle and the key is out of range the theft deterrent module locks the vehicle.
When keyless entry is used, personalization of systems is possible. They can be programmed to recognize different keys, with each driver having their own specific key. This allows for different settings to be made that are individual to each driver.
When a specific key is identified, the theft deterrent module communicates with the body control unit. Specific settings are remembered from that key, so the seat, steering wheel and mirror position automatically adjusts to the driver as well as climate control settings for cabin temperature and system modes. Entertainment system settings such as radio station presets, volume and audio settings; and transmission shift point preferences can all change to the driver’s individual preferences.
It also allows for a valet key to be used, limiting engine power and vehicle speed, and preventing any other vehicle settings from being changed.
Immobilization is where the theft deterrent system prevents the vehicle’s engine starting, or the transmission operating. Audible alarms may sound when either the locking or immobilization systems are tampered with.
