2.3 PEPS Block

PEPS functionality provides the user with a means to lock/unlock and start a vehicle just by having the electronic fob with them, without the need to actively interact with it. It consists of an LF coil driver placed in the vehicle, which generates a strong magnetic field on multiple (optional) LF PEPS antennas.

The passive fob implemented in the PEPS system can wake up on this LF field and receive the incoming data via the unidirectional LF link. The fob also measures the strength of the magnetic field, which is used to determine the position of the fob relative to the vehicle (outside or inside). Then, it encrypts the received challenge data (using AES) and returns the correct cipher response, together with the positioning information, to the vehicle via the unidirectional UHF link.