The system works by having a series of LF (low frequency 125 kHz) transmitting antennas both inside and outside the vehicle. The external antennas are located in the door handles. When the vehicle is triggered, either by pulling the handle or touching the handle, an LF signal is transmitted from the antennas to the key. The key becomes activated if it is sufficiently close and it transmits its ID back to the vehicle via RF (Radio frequency >300 MHz) to a receiver located in the vehicle. If the key has the correct ID, the PASE module unlocks the vehicle.paulcurtis wrote: ↑Wed Feb 10, 2021 3:47 amI don't know, so can only guess. Clearly by moving the key into the vehicle, it becomes activated. It then knows it's inside, and remains activated.Wdf76 wrote: ↑Tue Feb 09, 2021 8:55 amAbsolutely, for Pumas with keyless entry.paulcurtis wrote: ↑Tue Feb 09, 2021 7:00 am
Say the car is parked 2m from the front door, and you keep your keyless key just inside the front door. If the key remained active, then anyone could open the door (although not drive off). It would also mean the key could be hacked more easily. By deactivating after 40s, both issues are prevented. Plus the battery lasts longer. Win win.
However what is being transmitted by the key for cars equipped with keyless start?
The smart key determines if it is inside or outside the vehicle by measuring the strength of the LF fields. In order to start the vehicle, the smart key must be inside the vehicle.
This of course this will only work when your Key fob is 'awake' and able to receive and transmit as a result of senseing physical movement.