Hyundai Accent: Button Engine Start System / Description and Operation

- 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.

– Steering column locking with an ESCL device; Monitoring of the vehicle status to insure safe activation of the ESCL.

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

– Immobilizer function by LF transponder communication between fob and start/stop button.

– 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

– Steering column locking/unlocking with ESCL.

– 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. It also manages the locking and the unlocking of the steering column (called as ESCL)without any specific actions by the driver.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 push the start / stop button.

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

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

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	LED OFF
2	IG ACC	Amber color LED ON
3	IG ON (Engine OFF)	Blue color LED ON
4	Cranking	Maintain LED status before cranking
5	Engine running	LED OFF

Wireless Communication Electromagnetic waves are used to exchange information between the vehicle and the FOB. Two types of RKE Key can supplement the BES system:

– Non-smart key RKE

– SMART KEY FOB

Currently the BES system comprises with SMART KEY FOB always.The transmitter, receiver and antennas required for the communication between the fob and the vehicle will differ depending on functionalities and regional areas.The RKE and SMART KEY functions are in separated documents. Refer to Smart key system for more detailed information about SMART KEY function.Smart Key The SMK manages all function related to:

• "Start Stop Button (SSB) monitoring",

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

• "ESCL control",

• "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 ESCL/Terminal switching Operations”.It collects information about vehicle status from other modules (vehicle speed, alarm status, driver door open...), read the inputs (e.g. SSB, Lock Button and 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.Transponder

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.Two (2) LED colors are located in the center of the button to display of the status of the system. Another illumination LED is also integrated into the SSB for the lighting of the "Engine Start/Stop" characters.

Electronic Steering Column Lock (ESCL) The ESCL is needed to lock the steering column in order to prevent unauthorized usage of the vehicle. In order to achieve the required safety integrity level, the ESCL is controlled and monitored by the SMK. Such redundant architecture guarantees that the ESCL motor is supplied only during locking/unlocking operation and that it is disconnected from the battery and ground lines otherwise to avoid unexpected operation while the vehicle is in motion.Data are exchanged between the ESCL and SMK through an encrypted serial communication interface.

BES 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, ESCL and Engine status:

System State	Terminal Status	ESCL Status	Engine Status
1. OFF - Locked	OFF	Locked	Stopped
2. OFF - Unlocked	OFF	Unlocked	Stopped
3. ACC	ACC	Unlocked	Stopped
4. IGN	IGN1, IGN2, ACC	Unlocked	Stopped
5. Start	IGN1, Start	Unlocked	Cranking
6. IGN - Engine	IGN1, IGN2, ACC	Unlocked	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, ESCL and Engine status:

System State	Terminal Status	ESCL Status	Engine Status
1. OFF - UNLOCKED	OFF	Unlocked	Stopped
2. ACC	ACC	Unlocked	Stopped
3. IGN	IGN1, IGN2, ACC	Unlocked	Stopped
4. Start	IGN1, START with special pattern of activation see Chap 6.2.1 for details	Unlocked	Cranking
5. IGN - Engine	IGN1, IGN2, ACC	Unlocked	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.