Description and Operation

Description

The SMART KEY system allows the user to access and operate the vehicle conveniently. No traditional key or remote control is required to access the vehicle. The user carries the SMART KEY FOB, which requires no deliberate action by the user (such as pressing the RKE button). 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. Similarly, the electronic steering column lock (ESCL) is released. Again, communication between the vehicle and the SMART KEY FOB is required before any action. The system has the following features:

• Passive Unlock via Driver and Passenger Door
• Passive Lock via Driver and Passenger Door
• Passive Start
• Passive Trunk Access via Trunk Switch at Trunk Level
• Passive Lock via Liftgate
• 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) using the SMART KEY FOB. This function may differ depending on the platform, as follows:

   • Press the Door Handle Button
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 the user to release the ESCL and change power modes (Off, Accessory, Ignition), as well as start and stop the vehicle engine without performing any specific action using the SMART KEY FOB. See the specifications for the engine start system button.
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 Enable. It reads inputs (door handle button, Start/Stop button (SSB), PARK position switch), controls outputs (such as exterior and interior antennas), and communicates via CAN, as well as a simple linear interface for additional vehicle devices. To communicate with the SMART KEY FOB, the SMK ECU generates a request (polling) signal at 125 (or 134.2) kHz, encoded and modulated onto the induction antenna, and sends and receives the response from the SMART KEY FOB through 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 carrier signal at 125 (or 134.2) kHz distributed to the various 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 4 buttons (press).
• Transponder function in case of battery discharge or communication failure.

Antennas

1. 1
   AvG antennas transmit: Inductive antennas in and on the vehicle are used to convert current, controlled by the SMK ECU antenna driver, into a magnetic field at 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 liftgate. Up to three antennas cover the vehicle interior and the trunk or liftgate: two in the cabin and one in the trunk or liftgate.
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
   External receiver: The SMART KEY FOB response is received through the external AvD receiver, which is connected to the SMK ECU via a serial communication line. The SMK ECU has a connector pin for the serial communication line.

Door Handle. Both front door handles (driver and passenger) are equipped with antennas. AVG transmitters transmit signals at 125 (or 134.2) kHz. The front door handles are also equipped with a button. PRESS BUTTON. The button on the door handle serves as a trigger to indicate whether the user is attempting 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 liftgate.

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 in a free area at least 0.7 m from the antennas. The exterior antennas are integrated into the door handles, see illustration below. The access range to the trunk or liftgate is 0.7 m minimum, measured from the antenna position. The SMART KEY FOB receives and interprets the request sent by the vehicle through the exterior antennas in a free area at least 0.7 m from the exterior antennas integrated into the door handles, see illustration below. Passive Entry (Passive Access). Pressing one of the door handle buttons when all doors are closed indicates that the user wants to access the vehicle and triggers the unlock 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 triggers the lock system. Passive Trunk Opening. Pressing the trunk/liftgate switch when the trunk/liftgate is closed indicates the operator's intention to open the trunk/liftgate and triggers the system accordingly. As a result, the SMK ECU sends an AVG request to the SMART KEY FOB via the bumper exterior antenna. The SMART KEY FOB responds with an RF response. If the received response matches the expected one, the SMK ECU sends the message "open liftgate/trunk" over the CAN network. Passive Trunk Warning (sedan only). When the trunk is closed, the SMK ECU uses an appropriate search strategy to prevent the trunk buzzer from being activated by a FOB outside the vehicle. The SMK then searches for a SMART KEY FOB inside the trunk. If a valid SMART KEY FOB is detected in the trunk, the SMK ECU activates the external buzzer (TBD) to inform the user that a FOB was locked in the trunk. The SMK sends a trunk open command to the BCM to reopen the trunk if the trunk opening (BK) function is installed. For this function, "valid" SMART KEY FOB means any SMART KEY FOB belonging to the vehicle, even if it is DISABLED.Smart Key Reminder No. 1

1. 1
   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.
2. 2
   Event: The state of at least one door handle has changed from unlocked to locked.
3. 3
   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.
4. 4
   Preconditions: All terminals are OFF and at least one door is open (including securely) and there is no FOB-ADM and no lock status (check SMK every 100 ms while CAN/LIN is active).
5. 5
   Vehicle action: Closing the fifth door or trunk while in the locked handle state or with lock in progress.
6. 6
   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.
7. 7
   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.
8. 8
   If a valid FOB is not found, no action is required; but if the FOB is valid, the warning buzzer must be started.
9. 9
   If "b_Tailgate Option == On" and "b_Tailgate Lock Unlock Option == On" are met, the lock warning includes the tailgate, as the lock and unlock button for the door and trunk is treated as a door open switch.
10. 10
    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.
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 "b_Tailgate Option == On" and "b_Tailgate Lock Unlock Option == On" are met, the lock warning includes the tailgate, as the lock and unlock button for the door and trunk is treated as a door open switch.
13. 13
    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.
14. 14
    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.
15. 15
    If "b_Tailgate Option == On" and "b_Tailgate Lock Unlock Option == On" are met, the lock warning includes the tailgate, as the lock and unlock button for the door and trunk is treated as a door open switch.
16. 16
    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.
17. 17
    If a valid FOB is not found, a warning is triggered; but if a valid FOB is found, no action is started.

Smart Key Reminder 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). In case of SMART KEY FOB battery discharge or transmission failure, 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 trunk)
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 Voltage Detection. To detect a low FOB battery, battery voltage measurement and a low-voltage detection strategy are integrated into the FOB. Battery voltage measurement is performed when the FOB button is pressed or when an AVG measurement command is received. Teaching Description. This section describes the teaching procedure for the SMK, ESCL, and FOB. To teach the SMK, ESCL, and FOB, a connection using a diagnostic tool is required. TEACHING MODE. In any mode, the teaching process is controlled by the SMK. Before teaching begins, 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 ESCL and/or key ring, or to register additional keys in the existing system. This means the system has already been taught a specific PIN code. The PIN code is fixed for the entire service life of the vehicle, therefore the PIN code must be used in this mode. Otherwise, the teaching will fail. Coding Mode Procedure (Step by Step). Purpose: Key coding procedure at the dealership. Initial condition:

• SMK replacement: SMK is not learned, and ESCL and SMART FOB have already been learned with the same PIN code.
• ESCL replacement: ESCL is not learned, and SMK and SMART FOB have already been learned with the same PIN code.
• Coding additional or new keys: SMK and ESCL have already been learned with the same PIN code.

Protective Cover After Replacement (Empty Protective Cover). Startup is possible by following the process after replacing a new SMART KEY device, KEY FOB, or ESCL.

• This is for starting in the as-delivered (factory) state
• All parts related to this are in the factory-default state (Smart Key, ESCL ECM)
• ESCL is always unlocked in the initial state
• Depress the brake pedal while in P or N range.
• Press the Start/Stop button once with the dead Smart Key.