Hyundai Elantra AD: Smart Key System - Body Electrical System - Hyundai Elantra AD 2017-2020 Service ManualHyundai Elantra AD: Smart Key System

Specifications

Specifications
Smart Key Unit
Items
Specification
Rated voltage
DC 12V
Operating voltage
DC 9 ~ 16V
Operating temperature
-22°F ~ 167°F (-30°C ~ 75°C)
Load
Max. 4mA (When welcome light function off)

RF Receiver

Items
Specification
Frequency
433.92 Mhz
Antenna type
FSK (Frequency Shift Keying)

Smart Key Fob

Items
Specification
Battery
Lithium battery 3V 1EA
Distance
30m from vehicle, RF : 30m, Passive(LF) : 0.7m
Battery life
More than 2 years (10 times / a day)
  
An inappropriately disposed battery can be harmful to the environment and human health.
Dispose the battery according to your local law(s) or regulation.
Push buttons
4 (Door lock / unlock, Liftgate, Panic)
Frequency(Rx)
125 kHz
Frequency(Tx)
433.92 MHz
Numbers
2EA

Antenna

Items
Specification
Rated voltage
DC 12V
Operating voltage
DC 9 ~ 16V
Operating temperature
-22°F ~ 167°F (-30°C ~ 75°C)
Frequency
125kHz
Numbers
Interior(2EA), Door(2EA), Bumper(1EA), Trunk(1EA)

Components and Components Location

Component Location (1)

1. Interior antenna 1
2. Interior antenna 2
3. Door outside handle
4. Smart key unit (SMK)
5. Buzzer

Component Location (2)

1. Trunk open switch
2. Bumper antenna
3. Trunk atenna

Description and Operation

Description
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 :
Passive unlock via 4 doors
Passive locking via4 doors
Passive start
Passive access trunk via the trunk lid switch at the trunk
Max. 2 fobs can be handled by the system
Immobilizer backup antenna driver integrated into SSB for TP authentication (i.e. limp home mode)
Communication with engine management system
Communication with SRX
LF-RF communication
1. Passive unlock

The system allows the user to access (unlock) the vehicle without performing any actions with the SMART KEY FOB.

2. Passive locking

The system allows the user to lock the vehicle by pushing a button on door handle with the SMART KEY FOB.

3. Button start

The system allows the user to switch the power modes (Off, Accessory, Ignition), as well as to start and stop the vehicle’s engine without performing any actions with the SMART KEY FOB. See Button Engine Start system specification.

4. LIMP HOME Mode

Additionally, the system offers so called “limp home mode”, which is the user can operate all vehicle functions by pushing the key into the SSB.

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 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 125kHz 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 :
Power supply
Microcontroller with FLASH Memory
Single Line Interface to SRX
Single Line Interface to EMS
Input stage
LF antenna amplifier/driver
CAN communication with BCM
The LF antenna amplifier/driver generates a 125kHz 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 :

Passive functionality: receives LF-challenge and sends automatically RF response.
Classic RKE function by action up to 4 push buttons.
Transponder-functionality in case of a flat battery or a disturbed communication.
Antennas
1. Emitting LF Antennas :

Inductive antennas in and at the vehicle are used to transform the current, driven by the SMK ECU antenna driver, into a 125 (or 134.2) kHz magnetic field, which is the carrier for the SMART KEY challenge.

Three antennas cover the vehicle’s exterior: 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 tailgate.

Up to three antennas cover the vehicle’s interior and the trunk or tailgate interior: two in the passenger compartment and one in the tailgate room or trunk.

2. Bidirectional Immobilizer Antenna (for Limp Home) :

The Immobilizer Backup Antenna is used for sending and receiving data: it emits a magnetic field (125 - 135 kHz challenge) and receives changes in the field strength (response of Transponder).

3. Receiver

The SMART KEY FOB’s response is received via the RF receiver.

Door Handle

The front door handles of the two doors (driver door / passenger door) are equipped with emitting LF-antennas to emit the 125kHz signals. The front door handles are also equipped with a push button.

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 or tailgate lid.

Operation
Passive Functions

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.

Operating Range
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 or tailgate 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)

Push the door handle button 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:

At least one door is unlocked and two_steps timer is not running or
Two_steps timer is running and one of the push button except Front Left side is triggered
indicates the operator’s intent to lock the vehicle and thus triggers the system for a lock.

Passive Trunk Warning (Sedan Only)

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.

  
A blind spot in the trunk similar to any RF disturbance may lead to no trunk warning. Due to the penetration of the bumper antenna into the trunk area the lid may open without an Identification Device outside.
A blind spot in the trunk similar to any RF disturbance may lead to no trunk warning
Smart Trunk

When a user with a valid Smart Key in possession stands in the vicinity of the rear bumper (within LF antenna range) for over 3 seconds, the trunk is opened.

  
Function is set through the User Setting Mode (USM) in the Cluster.
1. Rear bumper antenna detects valid Smart Key in the vicinity.
2. When a valid Smart Key enters the rear bumper antenna range, alert buzzer and hazard lamp is activated 1 time to acknowledge detection.
  
Smart Key Unit can detect a Smart Key within 0.7~1 m of the rear bumper.
If the Smart Key stays inside the detection range, alert buzzer and hazard lamp is activated 1 time every second throughout the duration of the Smart Key remaining in the detection range.
3. If the Smart Key remains in the rear bumper detection range (antenna range) for over 3 seconds, alert buzzer and hazard lamp is activated 2 times and the trunk is opened.
Smart Key Reminder 1
1. Preconditions :

All terminals OFF & at least one door open & locking status is not locked checked by SMK periodically every 100ms, as long as CAN/LIN active.

2. Event:

At least 1 door knob status changed from unlock to lock.

3. SMK actions :
A. IF NO FOB-IN ACTIVE

SMK performs a search for the fobs in the interior of the vehicle. The same LF-strategy has to be used as it is defined for the ID out warning (registering only, no authentication

B. IF FOB-IN ACTIVE

SMK search valid TP

If no fob or no TP has been found, no action is required.

If any valid fob or valid TP has been found, SMK unlocks the vehicle by sending a CAN Key Reminder unlock message with the fob number.

If any valid fob has been found, SMK unlocks the vehicle by sending a CAN/LIN Key Reminder unlock message with the fob number.
Smart Key Reminder 2
1. Preconditions :

All terminals OFF & any door (including trunk) open & no FOB-IN & no locking status (checked by SMK periodically every 100ms, as long as CAN/LIN active)

2. Vehicle action :

Closing last door or trunk with knobs locked state, or with a locking in progress

3. SMK actions :

Before elapsing 500ms after the closing if all doors are locked then:

A. IF NO FOB-IN ACTIVE

SMK performs a search for the fobs in the interior of the vehicle.

The same LF-strategy has to be used as it is defined for the ID out warning (registering only, no authentication)
B. IF FOB-IN ACTIVE

SMK search valid TP

If no fob has been found, no action is required.

If any valid fob or valid TP has been found, SMK sends unlock command via CAN and activates ext. buzzer warning.

If any valid fob has been found, SMK sends unlock command via CAN/LIN and activates ext. buzzer warning.
Smart Key Door Lock Warning

Door Lock Warning 1

1. If terminal state is ACC or IGN and all doors are closed and that user triggers a SMK lock, a search is started at the exterior of the vehicle from the side of the trigger.
2. If no valid Fob is found no action is required, but if a valid Fob is found then a Buzzer warning shall be started.
3. If "b_Trunk Option == On" and "b_Trunk LockUnlockOption == On" are fullfilled, Lock warning is including tailgate as a door and tailgate lockunlock knob as a door unlock switch.
Door Lock Warning 2
1. If terminal state is OFF and not all doors are closed and that user triggers a SMK lock, a search is started at the exterior of the vehicle from the side of the trigger.
2. If no valid Fob is found no action is required, but if a valid Fob is found then a Buzzer warning shall be started.
3. If "b_Trunk Option == On" and "b_Trunk LockUnlockOption == On" are fullfilled, Lock warning is including tailgate as a door and tailgate lockunlock knob as a door unlock switch.
Door Lock Warning 3
1. If terminal state is OFF and ATWS is considered as Disarmed and all doors are closed and that user triggers a SMK lock, a search is started at the Interior of the vehicle;
2. if no valid Fob is found the search for SMK locking will be started, but if a valid Fob is found then a Buzzer warning shall be started.
3. If "b_Trunk Option == On" and "b_Trunk LockUnlockOption == On" are fullfilled, Lock warning is including tailgate as a door and tailgate lockunlock knob as a door unlock switch.
Smartkey Lamp Warning
1. If terminal state is ACC or IGN and vehicle speed is less than 3km/h, a periodic search (every 3s) is done at the interior of the vehicle to check that the valid fob is still in the in the vehicle.
2. If no valid Fob is found a Warning is started, but if a valid Fob is found then no action is started.
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:

Unlocking / locking of doors or trunk (or tailgate depending of the vehicle configuration): use of mechanical key
User Information Functions
ID OUT Warning
1. Preconditions :
A. (ACC or IGN1) & (any door open or trunk open)
2. Event:

The last opened door is closed

3. SMK action:

SMK searches for a SMART KEY FOB in the interior.

A. If no valid SMART KEY FOB is found, the SMK activates external buzzer and also sends ID OUT warning via CAN (exterior buzzer warning and internal buzzer warning).
B. If a door is opened and closed again during terminals on and inside valid fob, SMK re-enables the authentication and stops the warning. If the terminal is in ACC, SMK shall turn on immobilizer lamp.
  
If there is a LF error (LF overheating or LF antenna failure), the system will have the same behavior as it is with no fob found.
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.

Learning Description

In this chapter, the learning procedure for SMK and FOBs is described.

For the learning of the SMK and FOBs, it's necessary to have a connection to the diagnostic tool.

Learning MODE

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.

Teaching MODE

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

Initial state :
- SMK replacement: SMK is not learnt and SMART FOB are already learnt with same PIN code
- Additional or new keys teaching: SMK are already learnt with same PIN code

Starting After Replacing (Virgin Start)

Starting is possible by following process after replacing new smart key unit, FOB key.

It is for starting at virgin condition
All related parts are virgin condition (Smart key, ECM)
Press brake pedal in P or N range
Push the start button once with virgin smart key.

Smart Key Repair procedures

Smart Key
Smart Key Code Saving
1. Connect the DLC cable of GDS to the data link connector (16 pins) in driver side crash pad lower panel, turn the power on GDS.

2. Select the vehicle model and then do "Smart Key Code Saving".

3. After selecting "Smart Key Teaching" menu, push "Enter" key, then the screen will be shown as below.

4. After having the teaching smart key, push "Enter" key.
5. Input the "Pin Code" for first key teaching.

6. Press the SSB with smart key within 5 sec after pressing "OK".

7. Confirm the message "First key teaching completed".

8. Press the SSB with smart key within 5 sec after pressing "OK".

9. Confirm the message "Second key teaching completed".

10. Then the screen will be shown as below when key teaching process is completed.

Smart Key Unit Components and Components Location

Components (1)

No
Connector A
Connector B
Connector C
1
BAT (+)_Signal
Driver's door antenna_GND
-
2
BAT (+)_Power
Driver's door antenna_Power
-
3
IGN 1
-
-
4
IGN 2_Relay output
B-CAN (High)
SSB LED (OFF)
5
IGN 1_Relay output
B-CAN (Low)
SSB LED (IGN)
6
Assist door antenna_GND
Wheel speed sensor
SSB LED (ACC)
7
Interior antenna 2_GND
AT : 'P' signal input
MT : Clutch switch signal input
SSB Illumination (+)
8
Trunk antenna_GND
-
SSB Illumination (-)
9
Interior antenna 1_GND
C-CAN (Low)
Immoblizer antenna_GND
10
Bumpper antenna_GND
C-CAN (High)
Immoblizer antenna_Power
11
ACC
GND 1
-
12
IGN2
GND 2
Start signal feedback
13
ACC_Relay output
Assist door switch_signal
Stop lamp fuse
14
Starter_Relay output
Driver's door switch_signal
Brake switch
15
-
-
Immoblizer indicator
16
Assist door antenna_Power
EMS CAN
Exterior buzzer
17
Interior antenna 2_Power
ESCL CAN

18
Trunk antenna_Power
RPM_Input
19
Interior antenna 1_Power
SSB switch2
20
Bumpper antenna_Power
SSB switch1

Smart Key Unit Schematic Diagrams

Circuit Diagram

Smart Key Unit Repair procedures

Removal
Smart Key Unit
1. Disconnect the negative (-) battery terminal.
2. Remove the glove box.

(Refer to Body - "Glove Box Upper Cover Assembly")

3. Remove the smart key unit (A) after disconnecting the connectors (B) and loosening the bolt and nut.

Interior 1 Antenna
  
Take care not to scratch the crash pad and related parts.
1. Disconnect the negative (-) battery terminal.
2. Remove the console upper cover.

(Refer to Body - "Floor Console Assembly")

3. Remove the interior 1 antenna (B) after loosening the mounting nuts and disconnect the connector (A).

Interior 2 Antenna
1. Disconnect the negative (-) battery terminal.
2. Remove the console upper cover

(Refer to Body - "Floor Console Assembly")

3. Remove the interior 2 antenna (B) after loosening the mounting nuts (2EA) and disconnecting the connector (A).

Trunk Antenna
1. Disconnect the negative (-) battery terminal
2. Remove the rear transverse trim.

(Refer to Body - "Trunk Trim")

3. Remove the trunk antenna (B) after disconnect the connector (A) and loosening the mounting nuts.

Rear Bumper Antenna
1. Disconnect the negative (-) battery terminal.
2. Remove the rear bumper cover.

(Refer to Body - "Rear Bumper Cover")

3. Remove the rear bumper antenna (B) after disconnect the connector (A) and loosening the mounting nuts.

Buzzer
1. Disconnect the negative (-) battery terminal.
2. Remove the front left wheel guide.

(Refer to Body - "Front Wheel Guard")

3. Remove the buzzer (B) after disconnect the connector (A)

Door Outside Handle
1. Disconnect the negative (-) battery terminal.
2. Remove the front outside door handle.

(Refer to Body - "Front Door Outside Handle")

Inspection
Smart Key Unit

(Refer to Smart Key System - "Smart Key Diagnostic")

Smart Key Switch

(Refer to Smart Key System - "Smart Key Diagnostic")

Antenna

(Refer to Smart Key System - "Smart Key Diagnostic")

Door Outside Handle
1. Disconnect the front door outside handle connector (A).

2. Check for continuity between terminals No 3 and No 6.

No
Description
1
Door antenna (+)
2
Pocket lamp LED (+)
3
Door lock/unlock button switch
4
Door antenna (-)
5
Pocket lamp LED (-)
6
Door lock/unlock button switch ground

Installation
Smart Key Unit
1. Install the smart key unit.
2. Install the smart key unit mounting bolts and connect the connector.
3. Install the glove box.
4. Install the negative (-) battery terminal and check the smart key system.
Interior 1 Antenna
1. Install the interior 1 antenna.
2. Install the crash pad center panel.
3. Install the negative (-) battery terminal and check the smart key system.
Interior 2 Antenna
1. Install the interior 2 antenna.
2. Install the console rear complete assembly.
3. Install the negative (-) battery terminal and check the smart key system.
Trunk Antenna
1. Trunk mounted antenna.
2. Install the rear transverse trim.
3. Install the negative (-) battery terminal and check the smart key system.
Rear Bumper Antenna
1. Install the rear bumper antenna.
2. Install the rear bumper cover.
3. Install the negative (-) battery terminal and check the smart key system
Door Outside Handle
1. Install the outside handle.
2. Install the front outside door handle.
3. Install the negative (-) battery terminal and check the smart key system.

Smart Key Diagnostic Repair procedures

Inspection
Self Diagnosis with Scan Tool

It will be able to diagnose defects of SMART KEY system with GDS quickly. GDS can operates actuator forcefully, input/output value monitoring and self diagnosis.

The following three features will be major problem in SMART KEY system.
1. Problem in SMART KEY unit input.
2. Problem in SMART KEY unit.
3. Problem in SMART KEY unit output.
So the following three diagnosis operates will be the major problem solution process.
1. SMART KEY unit Input problem : switch diagnosis
2. SMART KEY unit problem : communication diagnosis
3. SMART KEY unit Output problem : antenna and switch output diagnosis
Switch Diagnosis
1. Connect the cable of GDS to the data link connector in driver side crash pad lower panel, turn the power on GDS.
2. Select the vehicle model and then SMART KEY system.
3. Select the "SMART KEY Unit".
4. After IG ON, select the "Current Data".

5. You can see the situation of each switch on scanner after connecting the "current data" process.

Display
Description
FL Toggle SW
ON : Push button is ON in the driver door handle.
FR Toggle SW
ON : Push button is ON in the assist door handle.
Tailgate open SW
ON : Tailgate button is ON.
Gear P Position
ON : Shift lever is P position.
IGN 1
ON : IGN switch is IG position.
ACC
ON : IGN switch is ACC position.
Brake SW
ON : Brake switch is ON.

Communication Diagnosis with GDS (Self Diagnosis)
1. Communication diagnosis checks that the each linked components operates normal.
2. Connect the cable of GDS to the data link connector in driver side crash pad lower panel.
3. After IG ON, select the "DTC".

Antenna Actuation Diagnosis
1. Connect the cable of GDS to the data link connector in driver side crash pad lower panel.
2. After IG ON, select the "Actation Test".

3. Set the smart key near the related antenna and operate it with a GDS.
4. If the LED of smart key is blinking, the smart key is normal.
5. If the LED of smart key is not blinking, check the voltage of smart key battery.
6. Antenna actuation
A. INTERIOR Antenna 1
B. INTERIOR Antenna 2
C. Trunk antenna
D. BUMPER/ Trunk Antenna
E. DRV_DR Antenna
F. AST_DR Antenna
Antenna Status Check
1. Connect the cable of GDS to the data link connector in driver side crash pad lower panel.
2. Select the "Antenna Status Check".

3. After IG ON, select the "Antenna Status Check".

4. Set the smart key near the related antenna and operate it with a GDS.

5. If the smart key runs normal , the related antenna, smart key(transmission, reception) and exterior receiver are normal.
6. Antenna status
A. INTERIOR Antenna 1
B. INTERIOR Antenna 2
C. BUMPER/ Trunk Antenna
D. DRV_DR Antenna
E. AST_DR Antenna
FOB Status Check
1. Connect the cable of GDS to the data link connector in driver side crash pad lower panel.
2. After IG ON, select the "FOB KEY STATUS INFO".

Smart Key Status Check
1. Connect the cable of GDS to the data link connector in driver side crash pad lower panel.
2. After IG ON, select the "SMK STATUS INFO".

Neutralization Status Check
1. Connect the cable of GDS to the data link connector in driver side crash pad lower panel.
2. After IG ON, select the "Neutralization mode".

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