|VELOSTER(FS) >2013 > G 1.6 T-GDI > Body Electrical System > Smart key System>Description and Operation|
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 :
Smart Key ECU (SMK ECU)
The SMK ECU manages all functions related to “Passive Unlock”, “Passive Lock” and “Passive Authorization for Engine Start Operation”.
It reads the inputs (Push button in door handle, Start Stop Button (SSB), PARK position Switch), controls the outputs (e.g. exterior and interior antennas), and communicates via the CAN/LIN (depends on the vehicle) as well as a single line interface to further devices of the car.
It reads the inputs (Push button in door handle, Start Stop Button (SSB), PARK position Switch), controls the outputs (e.g. exterior and interior antennas), and communicates via the CAN as well as a single line interface to further devices of the car.
For communication with the SMART KEY FOB, SMK ECU generates a request (challenge) as an encoded and modulated 125 kHz signal 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:
The LF antenna amplifier/driver generates a 125 kHz sinusoidal carrier signal which is distributed to the different antennas.
Smart Key FOB
The system supports up to 2 SMART KEY FOBs.
The main functions of the SMART KEY FOB are:
The front door handles of the two doors (driver door / passenger door) are equipped with emitting LF-antennas to emit the 125 kHz signals. The front door handles are also equipped with a 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 lid.
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.
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; refer to the below given picture. The trunk access range is also min. 0.7m measured from the antenna position.
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; refer to the below given picture
Passive Access (Passive Entry)
Pressing one of the push buttons in the door handles when all doors locked indicates the operator’s intent to access the vehicle and thus triggers the system for unlock
Passive Locking (Exit)
Pressing one of the push buttons in the door handles when one of the following condition is fulfilled:
indicates the operator’s intent to lock the vehicle and thus triggers the system for a lock.
Passive Open Tailgate
Pressing the Trunk Lid Switch when trunk is closed indicates the operator’s intent to open the trunk and thus triggers the system. Subsequently, the SMK ECU sends a LF-challenge to the SMART KEY FOB via the exterior bumper antenna. The SMART KEY FOB answers with a RF-response. If the received response matches the expected answer, SMK ECU sends a “trunk open” message via the CAN network.
Passive Trunk Warning
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.
Smart Key Reminder 1
Smart Key Reminder 2
Smart Key Door Lock Warning
Door Lock Warning 1
Door Lock Warning 2
Door Lock Warning 3
If no fob has been found, the passive locking is performed.
If any valid fob has been found, SMK ECU activates the external buzzer.
If the activity timer elapsed or ACC ON or IGN1 ON or NOT All door closed or FOB-IN, the SMK ECU stops the buzzer immediately.
After searching of inside fob, SMK ECU also performs a search for fobs outside of the vehicle.
Smart Key Lamp Warning
If any valid fob has been found, the SMK ECU stops the Key out indicator lamp and will (if one door is open) perform another search 3 seconds later. If no door is open then it’s only at the next when the preconditions are still valid, the search resumes by opening of one door.
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:
User Information Functions
Removing the PIF from the MSL and reinserting the PIF and pushing the MSL Knob will switch the lamp on again.
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 a LF measurement command is received.
If the fob has detected a low battery voltage, the LED will not be switched on at button press.
In this chapter, the learning procedure for SMK, FOBs is described.
For the learning of the SMK, FOBs, it's necessary to have a connection to the diagnostic tool.
Whatever the mode, the learning procedures are managed by the SMK.
Prior to start learning service, Fob-In signal must be active and the vehicle secret code (called as PIN code) should be known.
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