Smart Key Module System

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- Description

System Overview

The System offers the following features:

Human / machine interface through a 1-stage button, for terminal switching and engine start.

Control of external relays for ACC / IGN1 / IGN2 terminal switching and STARTER, without use of mechanical ignition switch.

Indication of vehicle status through LED or explicit messages on display.

Immobilizer function by LF transponder communication between fob and fob holder.

Redundant architecture for high system dependability .

Interface with Low Speed CAN vehicle communication network.

Interface with LIN vehicle communication network depending on platform .

The RKE and SMART KEY functions are not considered part of this Button Engine Start system and are specified in separated system.

System Main Function

Switching of ACC / IGN1 / IGN2 terminals.

Control of the STARTER relay BAT line (high side) based on communication with EMS ECU.

Management of the Immobilizer function.

Management of BES warning function.

Button Engine Start System

The Button Start System allows the driver to operate the vehicle by simply pressing a button (called as SSB) instead of using a standard mechanical key.

If the driver press the SSB while prerequisites on brakes, fob authentication and transmission status are satisfied, the BES System will proceed with the locking/unlocking of the steering column, the control of the terminal, and the cranking of the engine.

The driver can release the SSB as soon as this sequence initiated. After positive response from immobilizer interrogation, the system will activate the starter motor and communicate with the EMS to check the engine running status for starter release.

The driver will be able to stop the engine by a short push on the SSB if the vehicle is already in standstill. Emergency engine stop will be possible by a long press of the SSB or 3 consecutive presses in case the vehicle is in ENGINE RUNNING.

If the conditions for engine cranking are not satisfied while a push on the SSB is detected and a valid fob authenticated, the system will unlock the steering column and switch the terminals to IGN. Another push on the SSB will be necessary to start the engine.

In case of a vehicle equipped with SMART KEY system, fob authentication will not require any action from the driver. For limp home start or in case of vehicle without SMART KEY, the driver will have to insert the fob into the fob holder.

Control Ignition and engine ON/OFF by Sending signal to IPM.

Display status by LED Lamp ON/OFF. (Amber or Green)

Indicator ON/OFF Condition At Ignition Key Off Condition

No	Character lamp	Conditions
1	Indicator Lamp ON	Door open, Tail lamp ON, ACC, IG ON
2	Indicator Lamp 30sec ON → Lamp OFF	Door close, Tail lamp OFF, IG OFF
3	Indicator Lamp OFF	Remote LOCK, Passive LOCK
4	Rheostat at tail lamp ON (Illumination lamp)

Indicator ON/OFF Condition According To Ignition Key's Position

No	Ignition conditions	Start Button LED status
1	IG OFF	White color LED ON
2	IG ACC	Amber color LED ON
3	IG ON (Engine OFF)	Green color LED ON
4	Cranking	Maintain LED status before cranking
5	Engine running	LED OFF

Operation for Each Function of Button Starting

Electric power ON / Ignition ON
- The electric power is changed through OFF → ACC→IGN→OFF by pressing the button without stepping on the brake (Or with stepping on the brake) inside the car with FOB key (However, repeat ACC↔IGN when it is not in P. Converting to OFF is impossible.)
- The starting is ignited when the button is pressed with stepping on the brake at P/N position with FOB key.

Electric power OFF/ Ignition OFF
- The ignition OFF is possible in the state of vehicle stop. (Ignition OFF is possible in any position of ATM lever.)
- The lever shall be shifted for parking in gear N by pressing the ATM lever release button after electric power off in P.

How to off the ignition forcibly and to restart during driving
- It is a method of engine stop forcibly in vehicle topping down, fuel leaking and emergency (Ex: Accelerator pedal return failure)
- The engine is off and returned to the ACC state when the button is pressed for 2 seconds and more than 3 times successively within 3 seconds during driving. The restarting is available for next 30 seconds regardless of FOB key and the electric power is changed through OFF → ACC→IGN→OFF by pressing the button without stepping on the brake (or with stepping on the brake) inside the car with FOB key. (However, when it is not in P position, ACC↔IGN is repeated. The conversion to OFF is impossible.)

Function of 0.5 second delay for brake switch input.

The starting is available when the brake pedal is stepped on within 0.5 second after pressing the start button in engine OFF state.

State of start button indicator (LED) ON depending on the electric power state.
- Electric power OFF : LED OFF
- Electric power ACC state : Yellow LED ON
- Electric power ON : Blue LED ON
- During cranking : Maintaining the previous LED ON state before cranking
- Starting ON state : LED OFF

Limp Home Mode

When the input for the brake is not made (AT specification)

Moving to the "START" when SSB is pressed longer than 10 seconds in ACC state.

In case of problem in communication between EMS and CAN (Namely, not available for deciding the EMS state)

Moving to the state of "ENGINE RUN" from 'START" based on the RPM input

In case of short out of two SSB input line

The electric power cycling is available when SSB is pressed twice within 10 seconds (SSB LIMP HOME PRESS)

The buzzer rings when the button is pressed in the first time.

The electric power cycling is available and buzzer stops when the button is pressed twice within 10 seconds.

Smart Key Unit

The SMK manages all function related to:

"Start Stop Button (SSB) monitoring",

"Immobilizer communication" (with Engine Management System unit for immobilizer release),

"Authentication server" (Validity of Transponder and in case of Smart Key option Passive Fob authentication ),

"System consistency monitoring",

"System diagnosis",

Control of display message / warning buzzer .

The unit behaves as Master role in the whole system.

In case of SMART KEY application, for example "Passive Access”, "Passive Locking” and "Passive Authorization are integrated for Terminal switching Operations”.

It collects information about vehicle status from other modules (vehicle speed, alarm status, driver door open...), reads the inputs (e.g. SSB, Capacitive Sensor / Lock Button, PARK position Switch), controls the outputs (e.g. exterior and interior antennas), and communicates with others devices via the CAN network as well as a single line interfaces.

The diagnosis and learning of the components of the BES System are also handled by the SMK.

The SMK manages the functions related to the "terminal control" by activating external relays for ACC, IGN1 and IGN2. This unit is also responsible for the control of the STARTER relay.

The SMK is also controlling the illumination of the SSB as well as the "system status indicator", which consists of 2 LEDs of different color. The illumination of the fob holder is also managed by the SMK.

The SMK reads the inputs (Engine fob in, vehicle speed, relays contact status), controls the outputs (Engine relay output drivers), and communicates with others devices via the CAN.

The internal architecture of the SMK is defined in a way that the control of the terminal is secured even in case of failure of one of the two microcontrollers, system inconsistency or interruption of communication on the CAN network.

In case, failure of one of the two controllers, the remaining controller shall disable the starter relay. The IGN1 and IGN2 terminals relays shall be maintained in the state memorized before the failure and the driver shall be able to switch those IGN terminals off by pressing the SSB with EMERGENCY_STOP pressing sequence. However, engine restart will not be allowed. The state of the ACC relay will depend on the type of failure.

The main functions of the SMK are :

Control of Terminal relays

Monitoring of the Vehicle speed received from sensor or ABS/ESP ECU.

Control of SSB LEDs (illumination, clamp state).

Control of the base station located in SSB through direct serial interface.

System consistency monitoring to diagnose SMK failure and to switch to relevant limp home mode.

Providing vehicle speed information

Start Stop Button (SSB) monitoring

Starter power control

Start/Stop Button (SSB)

A single stage push button is used for the driver to operate the vehicle. Pressing this button allows:

To activate the power modes 'Off', 'Accessory', 'Ignition' and 'Start' by switching the corresponding terminals

To start the engine

To stop the engine

The contact will be insured by a micro-switch and a backlighting is provided to highlight the marking of the button whenever necessary.

Three (3) LED colors are located in the outside ring of the switch assy. They display the status of the system.

They are OFF(White) / ACC(Amber) / ON(Green).

BES (Button Engine Start) System State Chart

System States in Learnt Mode

In learnt mode, the BES System can be set in 6 different sates, depending on the status of the terminals and Engine status :

System State	Terminal Status	Engine status
1. OFF - Locked	OFF	Stopped
2. OFF - Unlocked	OFF	Stopped
3. ACC	ACC	Stopped
4. IGN	IGN1, IGN2, ACC	Stopped
5. Start	IGN1, Start	Cranking
6. IGN - Engine	IGN1, IGN2, ACC	Running (means "self-running")

Referring to the terminals, the system states described in the table above are same as those one found in a system based on a mechanical ignition switch.

The one of distinction with Mechanical-Ignition-Switch based system is that the BES system allows specific transition from [OFF] to [START] without going through [ACC] and [IGN] states.

System States In Virgin Mode

The BES System can be set in 5 different states (OFF LOCKED is not available in virgin mode), depending on the status of the terminals and Engine status :

System State	Terminal Status	Engine status
1. OFF - UNLOCKED	OFF	Stopped
2. ACC	ACC	Stopped
3. IGN	IGN1, IGN2, ACC	Stopped
4. Start	IGN1, START with special pattern of activation	Cranking
5. IGN - Engine	IGN1, IGN2, ACC	Running (means "self-running")

Referring to the terminals, the system states described in the table above are same as those one found in a system based on a mechanical ignition switch.

The one of distinction with Mechanical-Ignition-Switch based system is that the BES system allows specific transition from [OFF] to [START] without going through [ACC] and [IGN] states.

- 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

Passive unlock

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

Passive locking

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

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.

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

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.

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).

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.

Rear bumper antenna detects valid Smart Key in the vicinity.

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.

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

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.

Event:

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

SMK actions :
- 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
- 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

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)

Vehicle action :

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

SMK actions :

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

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.

If no valid Fob is found no action is required, but if a valid Fob is found then a Buzzer warning shall be started.

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

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.

If no valid Fob is found no action is required, but if a valid Fob is found then a Buzzer warning shall be started.

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

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;

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.

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

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.

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

Preconditions :
- (ACC or IGN1) & (any door open or trunk open)

Event:

The last opened door is closed

SMK action:

SMK searches for a SMART KEY FOB in the interior.
- 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).
- 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.

Item	Variant	Part #	Price
Ignition Lock · Power Switch	With Sport	95430F2510KEX	$105.27
Ignition Lock · Power Switch	Without Sport	93502F2500SSH	$129.90

Keyless Start / Stop Switch