Passive Functions

The system allows the user to access the vehicle without having to perform any actions (e.g. RKE button pressing) with the SMART KEY FOB. It is sufficient that a valid SMART KEY FOB is located within a defined and limited range with respect to the vehicle. So the system is capable of detecting and authenticating a SMART KEY FOB in the ranges as specified below.

Passive functions mean:

Passive Access
Passive Authentication

Operating Range

The SMART KEY FOB receives and interprets a challenge sent from the vehicle via the exterior antennas in a free space range of min. 0.7m measured around the exterior antennas which are integrated in the door handles; The trunk access range is also min. 0.7m measured from the antenna position.

Passive Access (Passive Entry)

Approaching one of the door handles with the integrated capacitive sensor indicates the operator's intent to access the vehicle and thus triggers the system.

Subsequently, the IPM sends a LF-challenge to the PIC FOB via the corresponding exterior door handle antenna. The PIC FOB answers with a RF-response.

If the received response matches the expected answer, the IPM issues an "unlock" message to the door control modules via the CAN network.

The system is able to distinguish between a PIC FOB on the driver or passenger side.

Special case: If the door is locked, but the ATWS is not armed, the IPM sends a sequence of silent telegrams at the interior antennas (interior antenna and hat shelf antenna) to avoid an unlocking with a fob inside the vehicle.