Smart Key System
Specifications
Specifications
Smart Key Unit
| Items | Specification |
| Rated Voltage | 12 V DC |
| Operating Voltage | 9–16 V DC |
| Operating Temperature | -40 - 176°F (-40 - 80°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/tailgate) 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 (3 pcs), door (2 pcs), bumper (1 pc) |
Components and Component Location
Component Location
| 1. Integrated Body Control Unit (IBU) 2. Interior Antenna 1 3. Interior Antenna 2 4. Tailgate Opening Switch 5. Bumper Antenna |
6. Tailgate Antenna 7. Buzzer 8. Start/Stop Button (SSB) 9. Door Handle and Door Antenna 10. Smart Key |
Description and Operation
Description
The SMART KEY system is a system that allows the user to access and operate the vehicle in a very convenient way. To access the vehicle, there is no need for a traditional key or remote control. A control unit is required.
The user carries the SMART KEY fob, which does not require any conscious action by the user (for example, pressing an RKE button). The SMART KEY system is activated by pressing the button on the door handle.
Once activated, 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 certain action (unlock, lock...) or remain inactive.
Again, communication between the vehicle and the SMART KEY FOB is required before any action can be performed.
The system provides the following functions:
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 into the SSB for TP authentication (i.e. keyless home mode).
Communication with Engine Management System
Communication with SRX
LF-RF Communication
Passive Unlock
The system allows the user to access (unlock) the vehicle without performing any action with the SMART KEY fob.
Passive Locking
The system allows the user to lock the vehicle by pressing the button on the door handle with the SMART KEY fob.
Start Button
The system allows the user to switch power modes (Off, Accessory, Ignition) and start and stop the engine without performing any action with the SMART KEY fob. See the Engine Start/Stop Button System specifications.
LIMP HOME Mode
In addition, the system features a so-called "Valet Mode", in which the user can control all vehicle functions by inserting the key into the SSB.
Smart Key Control Unit (SMK ECU)
The SMK ECU controls all functions related to passive unlocking, passive locking, and passive engine start authorization.
It reads inputs (door handle button, Start/Stop Button (SSB), PARK position switch), controls outputs (such as the external and internal antennas), and communicates via CAN, as well as via single-wire interface with other vehicle devices.
To communicate with the SMART KEY FOB, the SMK ECU generates a challenge as a coded and modulated 125 kHz signal on the inductive antenna outputs and receives the SMART KEY FOB response via the external radio frequency 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
The LF antenna amplifier/driver generates a sinusoidal carrier signal at 125 kHz, 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
Transmitting LF Antennas:
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. This field is the carrier for the SMART KEY challenge.
Three antennas cover the exterior of the vehicle: two antennas in the front door handles (driver and passenger side) 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 interior and the trunk or tailgate: two in the cabin and one in the trunk or tailgate.
Bidirectional Immobilizer Antenna (for Limp Home):
The backup immobilizer antenna is used to send and receive data: it radiates a magnetic field (125 - 135 kHz challenge) and detects changes in field strength (transponder response).
Receiver
The SMART KEY FOB response is received through the radio frequency receiver.
Door Handle
The front door handles (driver and passenger) are equipped with LF transmitting antennas to emit 125 kHz signals. The front door handles are also equipped with a button.
Press the
The button on the door handle serves as a trigger to indicate 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 having to perform any actions (for example, pressing the RKE button) with 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. In this way, the system is able to detect and authenticate the SMART KEY fob within the ranges specified below.
Operating Range
The SMART KEY FOB receives and interprets the challenge sent by the vehicle through the external antennas within a free-space radius of at least 0.7 m outside the antennas built into the door handles; refer to the illustration below. The access range to the trunk or tailgate is also at least 0.7 m from the antenna location.
The SMART KEY FOB receives and interprets the challenge sent by the vehicle through the external antennas within a free-space radius of at least 0.7 m outside the antennas built into the door handles; refer to the illustration below.
Passive Entry (Passive Access)
Pressing the door handle button when all doors are locked indicates the operator's intention to access the vehicle and therefore triggers 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 and one of the buttons, except the front left side, operate.
indicates the operator's intention to lock the vehicle and therefore activates the system to lock.
Passive Liftgate Warning (Sedan Only)
Whenever the liftgate is closed, the SMK ECU uses an appropriate search strategy to avoid the liftgate buzzer warning with the Smart Key outside the vehicle. The SMK then searches for a Smart Key inside the liftgate. If a valid Smart Key is found in the liftgate, the SMK ECU activates the SMK external buzzer (to be confirmed) to inform the user that the liftgate was closed with the Smart Key inside the liftgate.
The SMK will send a liftgate open command to the BCM to re-open the liftgate if the re-open bit (BK) is set. For this function, a "valid" Smart Key means any Smart Key fob registered to the vehicle, even if it is DEACTIVATED.
Smart Liftgate
When a user with a valid Smart Key stands near the rear bumper (within LF antenna range) for more than 3 seconds, the liftgate opens.
The rear bumper antenna detects a valid SMART KEY nearby.
When a valid SMART KEY enters the rear bumper antenna zone, the buzzer sounds and the hazard lamp flashes once to confirm detection.
If the Smart Key remains within the rear bumper detection range (antenna range) for more than 3 seconds, the buzzer and hazard lamps operate twice and the liftgate opens.
Welcome Light
When the driver with a Smart Key approaches the vehicle, the outside rear view mirrors and puddle lamps are controlled by Smart Key authentication.
Access to Welcome Light Search Mode (a mode that periodically searches for the SMART KEY to prevent vehicle battery discharge)
The vehicle enters the security state by RKE locking or passive locking by the driver.
The Smart Key Module (SMK) searches for the deactivated fob by controlling the internal antennas.
If the SMART KEY is not found in the vehicle, the Smart Key Module (SMK) will control the door handle antenna to search for the approaching driver.
The Smart Key Module (SMK) performs a search for 3 seconds, 3 times, by activating the door handle antenna. If the key is not found all 3 times, it will enter Welcome Light Search Mode.
If the outside mirror folding connection mode is activated, the mirror folding operation will be engaged.
Welcome Light On
In Welcome Light Search Mode, the SMART KEY is detected when the driver approaches the vehicle.
The Smart Key Module (SMK) sends a welcome lighting signal to the DDM for 15 seconds over CAN.
The DDM turns on the outside mirror puddle lamp for 15 seconds. (If the outside mirror folding is connected, the mirror folding operation will be engaged.)
Remote Start with Smart Key (Middle East and Asia Only)
Start the engine by pressing the remote start button on the Smart Key from a distance.
(Improves user convenience by activating the air conditioning system before boarding the vehicle.)
Signal reception distance: MIN 30 m (one-way signal)
Operating time: 10 minutes maximum
Operation Method
Engine start: 4 seconds after the door is locked, press and hold the remote start button for more than 2 seconds.
Engine stop: press the remote start button once.
Confirm start: the engine start can be confirmed by the hazard lamps flashing.
For safety: the engine will stop when the registered Smart Key is not inside the vehicle and the driver door is opened during remote start.
SMART KEY Reminder 1
Preconditions:
All terminals OFF, at least one door open, lock status not locked. Checked by SMK every 100 ms while CAN/LIN is active.
Event:
Status of at least one door handle has changed from unlocked to locked.
SMK Actions:
IF THE FOB IS NOT ACTIVE
SMK searches for fobs inside the vehicle cabin. The same LF strategy must be used as for the ID-out warning (registration only, no authentication).
IF THE FOB IS ACTIVE
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 by sending a CAN key unlock message with the fob number reminder.
If any valid fob is found, the SMK unlocks the vehicle by sending a CAN/LIN key unlock reminder with the fob number.
Smart Key Reminder 2
Preconditions:
All terminals OFF, any door (including the liftgate) open, FOB-IN and no lock status (checked by SMK periodically every 100 ms while CAN/LIN is active).
Vehicle action:
Closing the last door or liftgate while the handles are locked or with the lock in progress.
SMK Actions:
After 500 ms have elapsed following closing, if all doors are locked, then:
IF THE FOB IS NOT ACTIVE
SMK searches for fobs inside the vehicle cabin.
The same LF strategy must be used as for the ID-out warning (registration only, no authentication).
IF THE FOB IS ACTIVE
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 an unlock command over CAN and activates the additional buzzer warning.
If any valid FOB is found, SMK sends an unlock command via CAN/LIN and activates the additional buzzer warning.
Smart Key Door Lock Warning
Door Lock Warning 1
If the terminal status is ACC or IGN, all doors are closed, and this user triggers SMK lock, a search begins outside the vehicle from the trigger side.
If a valid fob is not found, no action is required, but if a valid fob is found, the buzzer warning must be activated.
If "Liftgate Option == On" and "Liftgate LockUnlockOption == On" are set, the lock warning treats the liftgate as a door and the liftgate handle unlock as a door unlock button.
Door Lock Warning 2
If the terminal status is OFF and not all doors are closed, and this user starts the SMK lock, the search begins outside the vehicle on the trigger side.
If a valid fob is not found, no action is required, but if a valid fob is found, the buzzer warning must be activated.
If "Liftgate Option == On" and "Liftgate LockUnlockOption == On" are set, the lock warning treats the liftgate as a door and the liftgate handle unlock as a door unlock button.
Door Lock Warning 3
If the terminal status is OFF and ATWS is considered disarmed and all doors are closed, and this user starts the SMK lock, the search begins inside the vehicle cabin.
if a valid fob is not found, the SMK lock search is started, but if a valid fob is found, an audible warning must be activated.
If "Liftgate Option == On" and "Liftgate LockUnlockOption == On" are set, the lock warning treats the liftgate as a door and the liftgate handle unlock as a door unlock button.
Smart Key Indicator Warning
If the final state is ACC or IGN and vehicle speed is less than 3 km/h, a periodic search (every 3 seconds) is performed inside the vehicle cabin to verify that a valid fob is still in the vehicle.
If a valid fob is not found, a warning is triggered, but if a valid fob is found, no action is triggered.
Fail-Safe Functions (Limp Home Backup)
If the SMART KEY FOB battery is discharged or communication fails, the following functions are available:
Door or liftgate (or liftgate depending on vehicle configuration) lock/unlock: use mechanical key
User Information Functions
ID OUT Warning
Preconditions:
(ACC or IGN1) & (any door or liftgate open)
Event:
Last open door closed
SMK Action:
SMK searches for the Smart Key fob in the cabin.
If a valid SMART KEY FOB is not found, SMK activates the exterior buzzer and sends the ID OUT warning via CAN (exterior buzzer, warning and interior buzzer).
If a door is opened and closed again while the terminals are switched on and off inside a valid fob, the SMK re-enables authentication and stops the warning. If the terminal is in ACC mode, the SMK must turn on the immobilizer lamp.
Low Fob Battery Voltage Detection
To detect a low battery condition of the FOB, a battery voltage measurement and low voltage detection strategy is implemented in the FOB. Battery voltage measurement is performed when the FOB button is pressed or when an LF measurement command is received.
Registration Description
This chapter describes the learning procedure for the SMK and FOB.
To register the SMK and FOB, a connection to the diagnostic tool is required.
REGISTRATION MODE
In any mode, the registration process is controlled by the SMK.
Before starting the registration service, the Fob-In signal must be active, and the vehicle security code (called the PIN code) must be known.
REGISTRATION MODE
This mode is used by dealers to replace the SMK and/or key set, or to register additional keys for an existing system. This means the system has already been learned with 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, learning will fail.
LEARNING MODE Procedure Description (Step by Step)
Purpose: Key registration procedure at a service station
Initial Condition:
SMK replacement: SMK is not registered, while the SMART FOB is already registered with the same PIN code.
Registering additional or new keys: SMKs are already registered with the same PIN code.
Starting after replacement (Virgin Start)
Starting is possible in the following order after replacing the new Smart Key ECU or FOB key.
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.
Test yourself
A quick Kia Stinger CK quiz: every answer comes with an explanation and a link to the manual page.