User's Manual

3. Outline of the system
A Smart Key system is a comfort feature that allows the user to lock, unlock without
using a mechanical key.
Once the user has accessed into the vehicle, with his Smart Key Fob he has the
possibility to switch between terminals (OFF-ACC-IGN) and to start the engine.
The user has to carry with him the Smart Key Fob as a wireless authentication is
performed when toggle button or Start Stop Button inputs are triggered.
3.1. Smart Key ECU
The SMK manages all functions related to “SMK Start”
The SMK unit reads the inputs (e.g. Start Stop Button), controls the outputs (e.g. exterior
and interior antennas), and communicates via the CAN network as well as a single line
interface to further devices of the car.
For communication with the SMART FOB, SMK generates a request (challenge) as an
encoded and modulated signal (134.2 kHz) at the inductive antenna outputs and
receives the SMART key FOB's response via the internal RF ANT and internal receiver.
The LF antenna amplifier/driver generates a sinusoidal carrier signal (134.2 kHz), which
is distributed to the different antennas. The signal is 100%-ASK modulated by switching
on and off the carrier.
3.2. LF Antennas:
Inductive antennas in and at the vehicle are used to transform the current, driven by the
SMK antenna driver, into a magnetic field (134.2 kHz), which is the carrier for the SMK
challenge.
One antenna covers the vehicle’s interior. One antenna covers the interior of the Trunk.
Two antennas in the Door Handles (Left side and Right side) cover the area around the
doors. One antenna in the rear bumper covers the area around the trunk for access to
the trunk.. Those antennas are based on ferrite core and have a pair of twisted copper
cables from antenna to pin header.
3.3. Transponder Antenna:
Built in the Start Stop Button to communicate with the transponder by a base
station and using wireless communication :(134.2kHz)
3.4. Installation
All of antennas and ECU will be installed permanently by professional engineers and end
user is not allowed to make any modification.