The SMART KEY system is a system that allows the user to
access and operate a vehicle in a very convenient way. To access the
vehicle, no traditional key or remote control unit is needed.
The user carries a SMART KEY FOB which does not require any
conscious actions by the user (e.g. operate a RKE button). The SMART KEY
system is triggered by pressing a push button in the door handle.
After being triggered the vehicle sends out a request in a
limited range. If the SMART KEY FOB receives this request, it
automatically sends a response to the vehicle. Then the system decides
whether to perform a particular action (unlocking, locking…) or remain
inactive.
Again, a communication between the vehicle and the SMART KEY FOB is needed before any actions will be performed.
The System offers the following features :
•
Passive unlock via 4 doors
•
Passive locking via 4 doors
•
Passive start
•
Passive trunk access via the trunk lid switch at the trunk
•
Max. 2 fobs can be handled by the system
•
Immobilizer backup antenna driver integrated into SSB for TP authentication (i.e. limp home mode)
•
Communication with engine management system
•
Communication with SRX
•
LF-RF communication
1.
Passive unlock
The system allows the user to access (unlock) the vehicle without performing any actions with the SMART KEY FOB.
2.
Passive locking
The system allows the user to lock the vehicle by pushing a button on door handle with the SMART KEY FOB.
3.
Button start
The system allows the user to release ESCL and to switch the
power modes (Off, Accessory, Ignition), as well as to enable and disable
the EV vehicle''s READY mode (standby) without performing any actions
with the SMART KEY FOB.
4.
LIMP HOME Mode
Additionally, the system offers so called "limp home mode",
by which the user can operate all vehicle functions by pushing the key
into the SSB.
Smart Key ECU (SMK ECU)
The SMK ECU manages all functions related to "Passive
Unlock", "Passive Lock" and "Passive Authorization for READY mode
operation".
It reads the inputs (from Push button in door handle, Start
Stop Button (SSB), PARK position Switch), controls the outputs (e.g.
from exterior and interior antennas), and communicates via the CAN as
well as a single line interface to further devices of the car.
To communicate with the SMART KEY FOB, SMK ECU generates a
request (challenge) in an encoded and modulated 125 (or 134.2) kHz
signals at the inductive antenna outputs and receives the SMART KEY
FOB''s response via the external RF receiver.
The main functional blocks of the SMK ECU are :
•
Power supply
•
Microcontroller with FLASH Memory
•
Single Line Interface to EMS
•
Input stage
•
LF antenna amplifier/driver
•
CAN communication with BCM
The LF antenna amplifier/driver generates a 125 (or 134.2)
kHz sinusoidal carrier signal which is distributed to different
antennas.
Smart Key FOB
The system supports up to 2 SMART KEY FOBs.
The main functions of the SMART KEY FOB are :
•
Passive functionality: receives LF-challenge and automatically sends RF response.
•
Classic RKE function by action of up to 4 push buttons.
•
Transponder-functionality in case of a flat battery or a disturbed communication.
Antennas
1.
Emitting LF Antennas:
Inductive antennas in and on the vehicle are used to
transform the current, driven by the SMK ECU antenna driver, into a 125
(or 134.2) kHz magnetic field, which is the carrier for the SMART KEY
challenge.
Three antennas cover the vehicle’s exterior: two antennas
in the Door Handles (DS and PS) cover the area around the doors; one
antenna in the rear bumper covers the area around the trunk or tailgate.
Up to three antennas cover the vehicle’s interior and the
trunk or tailgate interior: two in the passenger compartment and one in
the tailgate room or trunk.
2.
Bidirectional Immobilizer Antenna (for Limp Home):
The Immobilizer Backup Antenna is used for sending and
receiving data: it emits a magnetic field (125 - 135 kHz challenge) and
receives changes in the field strength (response of Transponder).
3.
Receiver
The SMART KEY FOB’s response is received via the RF receiver.
Door Handle
The front door handles of the two doors (driver door &
passenger door) are equipped with LF-antennas that emit 125 (or 134.2)
kHz signals. Each front door handle is also equipped with a push button.
Push Button
The push button in door handle serves as a trigger to indicate the user’s intent to unlock or lock the vehicle.
The push buttons are installed at front doors, integrated into the door handles.
Another button is installed at the trunk or tailgate lid.
Operation
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.
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 or tailgate access range is also min. 0.7m
measured from the antenna position.
Passive Access (Passive Entry)
Pressing one of the push buttons on the door handles while
all doors are locked indicates the operator''s intention to access the
vehicle and thus triggers the system to unlock.
Passive Locking (Exit)
Pressing one of the push buttons on the door handles when one of the following conditions is fulfilled:
•
At least one door is unlocked and two-step timer is not running or
•
Two-step timer is running and one of the push buttons except
front left side is triggeredindicates the operator''s intention to lock
the vehicle and thus triggers the system to lock.
Passive Trunk Warning (Sedan only)
Whenever the trunk is closed, SMK ECU uses a suitable search
strategy to avoid trunk buzzer warning by a fob outside the vehicle.
Then SMK searches for a SMART KEY FOB in the interior of the trunk. If a
valid SMART KEY FOB is found in the trunk, the SMK ECU activates SMK
external buzzer (TBD) to inform the user that the trunk has been closed
with a fob inside the trunk.
SMK will send the trunk open command to BCM for trunk
reopening if trunk reopening bit is set (BK). For this functionality, a
"valid" SMART KEY FOB means any SMART KEY FOB that belongs to the
vehicle, even if it''s DEACTIVATED.
•
A blind spot in the trunk similar to any RF disturbance may lead to no trunk warning.
•
Due to the penetration of the bumper antenna into the trunk area, the lid may open without an external Identification Device.
Smart Key Reminder 1
1.
Preconditions:
–
All terminals OFF
–
At least one door open
–
Locking status not locked (checked by SMK periodically for every 100 ms as long as CAN/LIN active)
2.
Event:
At least 1 door knob status changed from unlock to lock.
3.
SMK actions:
•
IF NO FOB-IN ACTIVE
SMK performs a search for the fobs in the interior of the
vehicle. The same LF-strategy has to be used as it is defined for the ID
out warning (registering only, no authentication)
•
IF FOB-IN ACTIVE
SMK search valid TP
If no fob or no TP has been found, no action is required.
If any valid fob or valid TP has been found, SMK unlocks the
vehicle by sending a CAN Key Reminder unlock message with the fob
number.
If any valid fob has been found, SMK unlocks the vehicle by sending a CAN/LIN Key Reminder unlock message with the fob number.
Smart Key Reminder 2
1.
Preconditions:
–
All terminals OFF
–
Any door (including trunk) open
–
No FOB-IN & no locking status (checked by SMK periodically for every 100 ms, as long as CAN/LIN active)
2.
Vehicle action:
Closes the last door or trunk with knobs in locked state or with locking in progress
3.
SMK actions:
Before 500 ms has elapsed after closing the door, if all doors are locked, the following actions are performed:
•
IF NO FOB-IN ACTIVE
SMK performs a search for the fobs in the interior of the vehicle.
The same LF-strategy has to be used as it is defined for the ID out warning (registering only, no authentication)
•
IF FOB-IN ACTIVE
SMK search valid TP
If no fob has been found, no action is required.
If any valid fob or valid TP has been found, SMK sends unlock command via CAN and activates ext. buzzer warning.
If any valid fob has been found, SMK sends unlock command via CAN/LIN and activates ext. buzzer warning.
Smart Key Door Lock Warning
Door Lock Warning 1
1.
If terminal state is ACC or IGN and all doors are closed and
that user triggers a SMK lock, a search is started at the exterior of
the vehicle from the side of the trigger.
2.
If no valid Fob is found no action is required, but if a valid Fob is found then a Buzzer warning shall be started.
3.
If conditions "b_TailgateOption = On" and
"b_TailgateLock/UnlockOption = On" are met, the lock warning operates as
in the doors. In this case, the tailgate lock/unlock feature operates
as in the door switch.
Door Lock Warning 2
1.
If terminal state is OFF and not all doors are closed and
that user triggers a SMK lock, a search is started at the exterior of
the vehicle from the side of the trigger.
2.
If no valid Fob is found no action is required, but if a valid Fob is found then a Buzzer warning shall be started.
3.
If conditions "b_TailgateOption = On" and
"b_TailgateLock/UnlockOption = On" are met, the lock warning operates as
in the doors. In this case, the tailgate lock/unlock feature operates
as in the door switch.
Door Lock Warning 3
1.
If terminal state is OFF and ATWS is considered as Disarmed
and all doors are closed and that user triggers a SMK lock, a search is
started at the Interior of the vehicle;
2.
if no valid Fob is found the search for SMK locking will be
started, but if a valid Fob is found then a Buzzer warning shall be
started.
3.
If conditions "b_TailgateOption = On" and
"b_TailgateLock/UnlockOption = On" are met, the lock warning operates as
in the doors. In this case, the tailgate lock/unlock feature operates
as in the door switch.
Smartkey Lamp Warning
1.
If terminal state is in ACC or IGN and vehicle speed is less
than 3km/h, a periodic search (for every 3s) is performed in the
interior of the vehicle to check that a valid fob is still in the
vehicle.
2.
If no valid Fob is found a Warning is started, but if a valid Fob is found then no action is started.
Failsafe Functions (Backup For Limp Home)
In case of a discharged battery of the SMART KEY FOB or disturbed transmission, the following functions are available:
•
Unlocking / locking of doors or trunk (or tailgate depending of the vehicle configuration): use of mechanical key
User Information Functions
ID OUT Warning
1.
Preconditions :
•
(ACC or IGN1) & (any door open or trunk open)
2.
Event:
The last opened door is closed
3.
SMK action:
SMK searches for a SMART KEY FOB in the interior.
•
If no valid SMART KEY FOB is found, the SMK activates
external buzzer and also sends ID OUT warning via CAN (exterior buzzer
warning and internal buzzer warning).
•
If a door is opened and closed again when the terminals are
on and valid fob is inside the vehicle, SMK re-enables the
authentication and stops the warning. If the terminal is in ACC, SMK
shall turn on immobilizer lamp.
If there is an LF error (LF overheating or LF antenna
failure), the system will behave in the same way as when no fob has been
found.
Fob Battery Low Voltage Detection
To detect fob low battery condition, certain battery voltage
measurement and low voltage detection strategy are implemented into fob.
The measurement of the battery voltage will be done if fob button is
pressed or if an LF measurement command is received.
Learning Description
In this chapter, the learning procedure for SMK and FOBs is described.
For the learning of the SMK and FOBs, it''s necessary to have a connection to the diagnostic tool.
Learning MODE
Whatever the mode, the learning procedures are managed by the SMK.
Prior to starting the learning service, Fob-In signal must be
active and the vehicle secret code (also referred to as PIN code)
should be known.
Teaching MODE
This mode is used by the dealers in order to replace SMK
and/or the set of keys, or to register additional keys for an existing
system. That means the system already has been learnt with certain PIN
Code. The PIN Code is fixed for the life time of the vehicle, therefore
the same PIN Code must be used in this mode. Otherwise learning will be
failed
Teaching MODE Procedure Description (Step By Step)
Objective : Key teaching procedure at service station
Initial state :
–
SMK replacement: SMK is not learnt and SMART FOB are already learnt with same PIN code
–
Teaching additional or new keys: SMK and ESCL are already learnt with same PIN code
Starting After Replacing (Virgin Start)
Starting is possible in the following process after replacing with a new smart key unit, FOB key or ESCL.
•
This method is used when starting in virgin condition.
•
All related parts are virgin condition (Smart key, PCM)
Inspection
Self Diagnosis With Scan Tool
Using the GDS, it can quickly diagnose defects of SMART KEY
system. GDS can operate actuator forcefully, monitor input/output values
and perform self d ...