Description and Operation

Description

The SMART KEY system allows the user to access and operate the vehicle conveniently. No traditional key or remote control operation is required to access the vehicle. The user carries the SMART KEY FOB, and no deliberate action by the user (such as pressing the RKE button) is required. The SMART KEY system is activated by pressing the button on the door handle. After activation, the vehicle sends a request within a limited area. 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 action (unlock, lock, etc.) or remain inactive. Again, communication between the vehicle and the SMART KEY FOB is required before any action. The system has the following features:

• Passive Unlock via 4 Doors
• Passive Lock via 4 Doors
• Passive Start
• Passive Access to the Rear Door using the tailgate switch located on the rear door.
• The system can use no more than 2 FOBs
• Driver Emergency Immobilizer Antenna, integrated into the SSB for TP authentication (for example, driving emergency mode)
• Communication with Engine Management System
• Communication with SRX
• AVG-AVD Communication

1. 1
   Passive Unlock. The system allows the user to access the vehicle without performing a specific action (unlocking) with the SMART KEY FOB.
2. 2
   Passive Lock. The system allows the user to lock the vehicle by pressing the button located on the door handle using the SMART KEY FOB.
3. 3
   Power Button. The system allows changing power modes (Off, Accessory, Ignition), as well as starting and stopping the vehicle engine, without performing a specific action with the SMART KEY FOB. Refer to Engine Start Button specifications.
4. 4
   RECOVERY DRIVING MODE. In addition, the system provides a so-called "recovery driving mode", which means that the user can operate 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 Permission. It reads inputs (door handle button, Engine Start/Stop Button (SSB), PARK position switch), controls outputs (e.g. exterior and interior antennas) and communicates via CAN, as well as a simple line interface for optional vehicle devices. To communicate with the SMART KEY FOB, the SMK ECU generates a request (polling) signal of 125 kHz, encoded and modulated onto the inductive antenna, and transmits and receives the response from the SMART KEY FOB via the external AvD receiver. The main functional blocks of the SMK ECU are:

• POWER SOURCE
• Flash Memory Microcontroller
• Single-Wire Interface to SRX
• Single-Wire Interface to EMS
• Initial Stage
• AvG Amplifier/Antenna Driver
• CAN Communication with BCM

Antenna Amplifier/Driver: AvG generates a sinusoidal 125 kHz carrier signal 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 AvG request and automatically sends the AvD response.
• Conventional RKE function using up to 3 buttons (press).
• Transponder function in case of battery discharge or communication failure.

Antennas

1. 1
   LF Transmitting Antennas: Inductive antennas inside and outside the vehicle are used to convert current controlled by the SMK ECU antenna driver into a magnetic field of 125 (or 134.2) kHz, the SMART KEY request carrier. Three antennas cover the exterior of the vehicle: two antennas inside the door handles (DS and PS) cover the area around the doors, and an antenna in the rear bumper covers the area around the trunk or tailgate. Up to three antennas cover the passenger compartment and the trunk or inside the tailgate: two in the cabin and one in the trunk or tailgate.
2. 2
   Bidirectional immobilizer antenna (for emergency driving): The backup immobilizer antenna is used to send and receive data: it emits a magnetic field (125 - 135 kHz request) and receives changes in field length (response from the transponder).
3. 3
   RECEIVER. The response from the SMART KEY FOB is received through the radio frequency receiver.

Door Handle: The driver and passenger door handles are equipped with AvG transmitting antennas for sending 125 kHz signals. The front door handles are also equipped with a button. PUSH BUTTON: The button on the door handle serves as a trigger to indicate whether the user is trying to unlock or lock the vehicle. The buttons are installed on the front doors, integrated into the handles. Another button is installed on the trunk or tailgate lid.

Operation

Passive Functions. The system allows the user to access the vehicle without performing any action (for example, pressing an RKE button) using the SMART KEY FOB. It is sufficient that the SMART KEY FOB is located within the restricted zone defined relative to the vehicle. Thus, the system is able to detect and authenticate the SMART KEY FOB in the areas specified below.

Operating Range

The SMART KEY FOB receives and interprets the request sent by the vehicle through the exterior antennas within a free area of at least 0.7 m from the antennas. The exterior antennas are integrated into the door handles; see the illustration below. The access range to the trunk or tailgate is 0.7 m minimum, measured from the antenna position. Passive Entry (Passive Entrance): Pressing the door handle button when all doors are locked indicates the operator's intention to access the vehicle and starts the unlocking system. Passive Lock (Exit): Press one of the buttons on the door handle when one of the following conditions is met:

• at least one door is unlocked and the two-stage timer is not running, or
• the two-stage timer is running and one of the buttons other than the front left side is pressed

indicates that the user wants to lock the vehicle and therefore starts the locking system. Passive Tailgate Warning (sedan only): When the trunk lid is closed, the SMK ECU uses an appropriate search strategy to prevent the rear door buzzer from sounding when the SMART KEY FOB is outside the vehicle. The SMK then searches for the SMART KEY FOB inside the tailgate. If a valid SMART KEY is inside the trunk, the SMK ECU activates the exterior buzzer to inform the user that the tailgate is being closed with the key inside the trunk. The SMK sends a tailgate open command to the BCM to reopen the tailgate if the tailgate open function (BK) is enabled. For this function, a "valid" SMART KEY FOB means any SMART KEY FOB belonging to the vehicle itself, if it is turned OFF.Smart Tailgate: When the user holds a valid SMART KEY near the rear bumper (within the LF antenna range) for more than 3 seconds, the tailgate opens.

1. 1
   The rear bumper antenna detects a nearby valid Smart Key.
2. 2
   When a valid Smart Key enters the rear bumper antenna zone, the buzzer and hazard warning lights activate once to confirm detection.
3. 3
   If the Smart Key remains in the rear bumper zone (antenna range) for more than 3 seconds, the buzzer and hazard warning lights activate twice and the tailgate opens.
4. 4
   Preconditions: All terminals are OFF, and at least one door is open and not in the locked state. Check SMK every 100 ms while CAN/LIN is active.
5. 5
   Event: The state of at least one door handle has changed from unlocked to locked.
6. 6
   SMK Actions:

   • IF NO ACTIVE ADM-FOB: SMK searches for FOBs inside the vehicle. Use the same AvG strategy as described above for the exit ID warning (recording only, not identification).
   • IF DM-FOB IS ACTIVE: SMK searches for a valid TP.

   If no FOB or TP is found, no action is required. If a valid FOB or TP is found, SMK unlocks the vehicle by sending a CAN Key Reminder message with the FOB number. If a valid FOB is found, SMK unlocks the vehicle by sending a CAN/LIN key reminder message with the FOB number.
7. 7
   Prerequisites: All terminals OFF, at least one door open (including the tailgate), and no FOB-ADM and no lock status (check SMK every 100 ms while CAN/LIN is active).
8. 8
   Vehicle Action: Closing the liftgate or tailgate in the locked state of the handle or with lock in progress.
9. 9
   SMK Actions: Within 500 ms after closing, if all doors are locked, then:

   • IF NO ACTIVE ADM-FOB: SMK searches for FOBs inside the vehicle. Use the same AvG strategy as described above for the exit ID warning (recording only, not identification).
   • IF DM-FOB IS ACTIVE: SMK searches for a valid TP.

   If no FOB is found, no action is required. If a valid FOB or TP is found, SMK sends an unlock command via CAN and activates the external buzzer. If a valid FOB is found, SMK sends an unlock command via CAN/LIN and activates the external buzzer.
10. 10
    If the terminal state is ACC or ALL, all doors are closed, and the user starts SMK locking, a search begins outside the vehicle from the trigger side.
11. 11
    If a valid FOB is not found, no action is required; but if the FOB is valid, the warning buzzer must be started.
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 tailgate lock and unlock button is treated as a door open switch.
13. 13
    If the terminal state is OFF and not all doors are closed, and the user starts SMK locking, a search begins outside the vehicle from the trigger side.
14. 14
    If a valid FOB is not found, no action is required; but if the FOB is valid, the warning buzzer must be started.
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 tailgate lock and unlock button is treated as a door open switch.
16. 16
    If the terminal state is OFF, ATWS is considered disarmed, all doors are closed, and the user starts SMK locking, a search begins inside the vehicle.
17. 17
    If a valid FOB is not found, the SMK locking search is started, but if a valid FOB is found, the warning buzzer must be started.
18. 18
    If "Rear Door Option == On" and "Rear Door LockUnlockOption == On" are set, the lock warning includes the rear door as a door, and the tailgate lock and unlock button is treated as a door open switch.
19. 19
    If the terminal state is ACC or ALL and vehicle speed is below 3 km/h, a periodic search (every 3 s) is performed inside the vehicle to confirm that a valid FOB is still in the vehicle.
20. 20
    If a valid FOB is not found, a warning is triggered; but if a valid FOB is found, no action is started.

Reminder Smart Key No. 1; Reminder Smart Key No. 2; Smart Key Door Lock Warning; Door Lock Buzzer 1; Door Lock Buzzer 2; Door Lock Buzzer 3; Smart Key Warning Lamp; Fail-Safe Functions (Rescue for Breakdown Driving): If the SMART KEY FOB battery is discharged or transmission fails, the following functions are available:

• Unlocking/locking doors or trunk (or liftgate), depending on vehicle equipment: using manual key

Functions. User Information.

Exit ID Warning

1. 1
   Preconditions:

   • (ACC or ALL1) and (open door or open tailgate).
2. 2
   Event: The last open door is closed.
3. 3
   SMK action: SMK searches inside for the SMART KEY FOB.

   • If a valid SMART KEY FOB is not found, SMK activates the external warning buzzer and also sends an EXIT ID warning via CAN (external warning buzzer and interior warning chime).
   • If a door is opened and then closed again while the terminals are activated, and a valid interior SMK FOB allows re-authentication, the warning is disabled. If the terminal is in the ACC position, SMK turns on the immobilizer indicator lamp.

FOB Low Battery Detection. To detect a low battery in the FOB, battery voltage measurement and a low voltage detection strategy are integrated into the FOB. Battery voltage measurement is performed when a button on the FOB is pressed or when an AVG measurement command is received. Description of Registration. This section describes the registration procedure for SMK and FOB. To register the SMK and FOB, communication with the diagnostic tool is required. REGISTRATION MODES. In any mode, the registration process is controlled by the SMK. Before starting registration, the Fob-Adm signal must be active and the vehicle secret code (called the PIN code) must be known. CODING MODE. This mode is used by technicians to replace the SMK and/or key set, or to register additional keys to an existing system. This means the system is already registered with a specific PIN code. The PIN code is fixed; therefore, the PIN code must be used in this mode for the entire service life of the vehicle. Otherwise, registration will fail. Coding Mode Procedure (Step by Step). Task: Key coding procedure at the dealership. Initial condition:

• SMK Replacement: SMK not registered, Smart FOB already registered with the same PIN code.
• Coding of Additional or New Keys: SMK already registered with the same PIN code.

Protective Cover After Replacement (Blank Protective Cover). Start-up is possible by following the procedure after replacing the new Smart Key unit and FOB.

• This is for starting in the as-delivered (factory) state
• All parts in original condition (Smart Key, ECM).
• Depress the brake pedal while in P or N range.
• Press the Start/Stop button once with the dead Smart Key.