Smart Key System

Specifications

Specifications

Smart Key Unit

Items	Specification
Rated Voltage	12 V DC
Operating Voltage	9–16 V DC
Operating Temperature	-31 - 167°F (-35 - 75°C)
Load	Max. 4 mA (with welcome light function OFF)

RF Receiver

Items	Specification
Frequency	433.92 MHz
Antenna Type	FSK (Frequency Shift Keying)

Smart Key Fob

Items	Specification
Battery	3V Lithium Battery 1EA
Range	- Distance at which the RF (radio frequency) receiver can receive the FOB transmission signal: 30 m. - Distance at which the LF (low frequency) antenna (outside handle/trunk/rear door) can detect the FOB: 0.7 m
Battery Life	More than 2 years (10 times/day)
Press the buttons	3 (door lock/unlock, tailgate)
Frequency (Reception)	125 kHz
Frequency (Transmission)	433.92 MHz
Quantity	2 pcs

Antenna

Items	Specification
Rated Voltage	12 V DC
Operating Voltage	9–16 V DC
Operating Temperature	-22 - 167°F (-30 - 75°C)
Frequency	125 kHz
Quantity	Interior (2 pcs), door (2 pcs), bumper (1 pc)

Components and Component Location

Component Location (1)

1. Smart Key Unit (SMK) 2. Interior antenna 1

3. Buzzer 4. Outside door handle/door antenna

Component Location (2)

1. Interior antenna 2 2. Rear door open switch

3. Bumper Antenna

Description and Operation

Description

The SMART KEY system allows the user to access and operate the vehicle in a very convenient way. No traditional key or remote control is required to access the vehicle. The user carries the SMART KEY FOB, which does not require any conscious action by the user (such as pressing an RKE button). The SMART KEY system is triggered when the door handle button is pressed. After activation, the vehicle sends a request within a limited range. If the SMART KEY FOB receives this request, it automatically sends a response to the vehicle. The system then decides whether to perform a specific function (unlock, lock…) or remain inactive. Again, communication between the vehicle and the SMART KEY FOB is required before any function is performed. The system offers the following features:

• Passive Unlock via 4 Doors
• Passive Lock via 4 Doors
• Passive Start
• Passive Tailgate Access via Tailgate Switch
• A maximum of 2 fobs can be processed by the system
• Immobilizer backup antenna driver is integrated in the SSB for TP authentication (i.e., in idle mode)
• Communication with Engine Management System
• Communication with SRX
• LF-RF Communication

1. 1
   Passive Unlock. The system allows the user to access (unlock) the vehicle without performing any action with the SMART KEY fob.
2. 2
   Passive Lock. The system allows the user to lock the vehicle by pressing the button on the door handle with the SMART KEY fob.
3. 3
   Start Button. The system allows the user to switch power modes (OFF, ACC, IGN), as well as start and stop the vehicle engine, without performing any actions with the SMART KEY fob. Refer to Engine Start/Stop Button System Specification.
4. 4
   LIMP HOME Mode: In addition, the system provides a so-called 'limp home mode', in which the user can control all vehicle functions by inserting the key into the SSB.

SMART KEY ECU (SMK ECU). The SMK ECU controls all functions related to Passive Unlock, Passive Lock and Passive Engine Start Authorization. It reads inputs (door handle button, Start/Stop Button (SSB), PARK position switch), controls outputs (such as the exterior and interior antennas), and communicates via both CAN and LIN interfaces with other vehicle devices. To communicate with the SMART KEY FOB, the SMK ECU generates a request (challenge) as an encoded and modulated 125 kHz signal on the inductive antenna outputs and receives the SMART KEY FOB response through an external RF receiver. The main functional blocks of the SMK ECU are:

• Power Supply
• Flash Memory Microcontroller
• Single-Wire Interface to SRX
• Single-Wire Interface to EMS
• Input Stage
• LF Antenna Amplifier/Driver
• CAN Communication with BCM

LF Antenna Amplifier/Driver generates a sinusoidal 125 kHz carrier signal, which is distributed to the different antennas. SMART KEY FOB The system supports up to 2 SMART KEY FOBs. Main functions of the SMART KEY FOB:

• Passive Function: receives the LF call and automatically sends an RF response.
• Classic RKE function using up to 3 buttons.
• Transponder operation in case of battery discharge or communication failure.

Antennas

1. 1
   LF Transmitting Antennas: Inductive antennas in and on the vehicle are used to convert the current controlled by the SMK ECU antenna driver into a magnetic field at a frequency of 125 (or 134.2) kHz, which is the carrier for the SMART KEY call. Three antennas cover the exterior of the vehicle: 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 rear door. Up to three antennas cover the vehicle interior and the trunk or rear door interior: two in the cabin and one in the trunk or rear compartment.
2. 2
   Bidirectional Immobilizer Antenna (for Limp Home): The backup immobilizer antenna is used to send and receive data: it emits a magnetic field (125 - 135 kHz call) and receives changes in field strength (transponder response).
3. 3
   Receiver. The SMART KEY fob response is received through the RF receiver.

Door Handle. The front handles of both front doors (driver/passenger) are equipped with transmitting LF antennas for sending 125 kHz signals. The front door handles are also equipped with a button. Pressing the door handle button serves as a trigger indicating the user's intention to unlock or lock the vehicle. The buttons are installed on the front doors, built into the door handles. Another button is installed on the trunk lid or tailgate.

Operation

Passive Functions. The system allows the user to access the vehicle without performing any action (such as pressing an RKE button) on the SMART KEY FOB. It is sufficient for a valid SMART KEY FOB to be within a specified and limited range relative to the vehicle. Thus, the system is able to detect and authenticate the SMART KEY FOB within the ranges below.

Operating Range

The SMART KEY FOB receives and interprets the request sent from the vehicle through the exterior antennas in free space within a minimum radius of 0.7 m measured around the exterior antennas built into the door handles; refer to the illustration below. The access range for the trunk or tailgate is also a minimum of 0.7 m from the antenna location. Passive Entry (Passive Entry): Pressing the door handle button when all doors are locked indicates the operator's intention to access the vehicle, and thus activates the system to unlock. Passive Lock (Exit): Pressing one of the door handle buttons when one of the following conditions is met:

• At least one door is open and the two-step timer is not running, or
• The two-step timer is running and one of the buttons other than the front left one is activated.

indicates the operator's intention to lock the vehicle and thereby activates the locking system. Passive Rear Door Warning (Sedan Only): Whenever the trunk lid is closed, the SMK ECU uses an appropriate search strategy to avoid a rear door buzzer warning when the FOB is outside the vehicle. The SMK then searches for a SMART KEY FOB inside the trunk lid. If a valid SMART KEY FOB is inside the trunk lid, the SMK ECU activates the SMK external buzzer (to be confirmed), informing the user that the trunk lid has been closed with the FOB inside the trunk lid. The SMK will send a rear door open command to the BCM to reopen the rear door if the rear door reopen bit (BK) is set. For this function, a 'valid' SMART KEY FOB means any SMART KEY FOB belonging to the vehicle, even if it is DEACTIVATED.SMART KEY Reminder 1

1. 1
   Preconditions: All terminals OFF and at least one door open and lock status not locked. Checked by SMK every 100 ms while CAN/LIN is active.
2. 2
   Event: Status of at least 1 door handle changed from unlocked to locked.
3. 3
   SMK Actions:

   • IF the FOB is not active, the SMK searches for FOBs inside the vehicle. The same LF strategy must be used, as it is defined for the no-ID warning. (Registration only, no authentication)
   • IF the FOB is ACTIVE, the SMK searches for a valid TP.

   If no FOB or TP is found, no action is required. If any valid FOB or valid TP is detected, the SMK unlocks the vehicle, sending a CAN Key Reminder unlock message with the FOB number. If any valid FOB is detected, the SMK unlocks the vehicle by sending a CAN/LIN Key Reminder unlock message with the FOB number.
4. 4
   Preconditions: All terminals OFF, any door (including the rear door) open, and no FOB-IN and no lock (checked by SMK periodically every 100 ms while CAN/LIN is active).
5. 5
   Vehicle action: Closing the last door or trunk with the handles locked or while locking is in progress.
6. 6
   SMK actions: 500 ms after closing, if all doors are locked, then:

   • IF the FOB is not active, the SMK searches for FOBs inside the vehicle cabin. Use the same LF strategy as for the ID OUT warning (registration only, no authentication).
   • IF the FOB is ACTIVE, the SMK searches for a valid TP.

   If no FOB is found, no action is required. If any valid FOB or valid TP is found, the SMK sends a CAN unlock command and activates the additional buzzer warning. If a valid FOB is found, the SMK sends a CAN/LIN unlock command and activates the additional buzzer warning.
7. 7
   If the terminal status is ACC or IGN, all doors are closed, and this user triggers the SMK lock, the search starts outside the vehicle from the trigger side.
8. 8
   If no valid FOB is found, no action is required, but if a valid FOB is found, the buzzer warning must be activated.
9. 9
   If 'Rear Door Option == On' and 'Rear Door LockUnlockOption == On' are set, the lock warning includes the rear door as a door, and the rear door handle lock/unlock is used as the door unlock switch.
10. 10
    If the terminal status is OFF, and not all doors are closed, and this user triggers the SMK lock, the search starts outside the vehicle from the trigger side.
11. 11
    If no valid FOB is found, no action is required, but if a valid FOB is found, the buzzer warning must be activated.
12. 12
    If 'Rear Door Option == On' and 'Rear Door LockUnlockOption == On' are set, the lock warning includes the rear door as a door, and the rear door handle lock/unlock is used as the door unlock switch.
13. 13
    If the terminal status is OFF, the ATWS is considered disarmed, all doors are closed, and this user triggers the SMK lock, the search starts from the vehicle interior.
14. 14
    If no valid FOB is found, the SMK lock search will be started, but if a valid FOB is found, then the audible warning must be activated.
15. 15
    If 'Rear Door Option == On' and 'Rear Door LockUnlockOption == On' are set, the lock warning includes the rear door as a door, and the rear door handle lock/unlock is used as the door unlock switch.
16. 16
    If the final state is ACC or IGN and the vehicle speed is less than 3 km/h, a periodic search (every 3 seconds) is performed inside the vehicle to make sure the valid key fob is still in the vehicle.
17. 17
    If a valid FOB is not found, the warning is triggered, but if a valid FOB is found, no action is triggered.

SMART KEY Reminder 2 SMART KEY Door Lock Warning Door Lock Warning 1 Door Lock Warning 2 Door Lock Warning 3 Smart Key Indicator Warning Fail-Safe Functions (Limp Home Backup) If the SMART KEY FOB battery is discharged or transmission fails, the following functions are available:

• Unlocking/locking doors or trunk (or rear door depending on vehicle equipment): with mechanical key

User Information Functions

ID OUT Warning

1. 1
   Preconditions:

   • (ACC or IGN1) & (any door or liftgate open)
2. 2
   Event: Last open door closed
3. 3
   SMK action: SMK searches for the SMART KEY FOB inside the cabin.

   • If a valid SMART KEY fob is not found, the SMK activates the external buzzer and also sends an ID OUT warning via CAN (external buzzer and internal chime warning).
   • If a door is opened and closed again while the terminals inside and outside the fob are active, the SMK restarts authentication and stops the warning. If the terminal is in the ACC position, the SMK must activate the immobilizer lamp.

FOB Battery Low Voltage Detection: For FOB battery low detection, the battery voltage measurement and low voltage detection strategy are implemented in the FOB. The battery voltage measurement will be performed when the FOB button is pressed or when an LF measurement command is received. Teaching Description: This chapter describes the teaching procedure for the SMK and FOBs. A connection to the diagnostic tool is required to teach the SMK and FOBs. TEACHING MODE: In any mode, the teaching process is controlled by the SMK. Before starting the teaching service, the Fob-In signal must be active and the vehicle secret code (called the PIN code) must be known. TEACHING MODE: This mode is used by dealers to replace the SMK and/or key set or to register additional keys to an existing system. This means the system is already taught a specific PIN code. The PIN code is fixed for the entire service life of the vehicle, so the same PIN code must be used in this mode. Otherwise, teaching will fail. TEACHING MODE: Procedure Description (step by step). Purpose: Key teaching procedure at the service station. Initial condition:

• SMK replacement: SMK not learned, and SMART FOB already learned with the same PIN code
• Learning additional or new keys: SMK already learned with the same PIN code

Starting After Replacement (Initial Start). Starting is possible in the following sequence after replacing the new SMART KEY or fob.

• This is for starting from the virgin state
• All related parts in initial state (smart key, ECM)
• Depress the brake pedal in P or N range
• Press the start button once with the virgin smart key.