Description and Operation

Description

GENERAL DESCRIPTION OF THE SYSTEM The system has the following features:

• Changing the ignition and power state of the engine using the Start button.
• Control of external relays to switch the ACC/ALL1/IGN2 and STARTER terminals, without using a mechanical ignition switch.
• Display of the vehicle state on the indicator using an LED or clear messages.
• Immobilizer function through AVG transponder communication between the key fob and the vehicle.
• Redundant architecture for high system reliability
• Interface with the vehicle low-speed CAN communication network.
• Interface with the vehicle LIN communication network, depending on the platform.

The RKE and SMK functions are not considered part of this engine start button system and are specified in a separate system. Main function of the system

• Switching of ACC/ALL1/ALL2 terminals.
• Control of the BAT (high side) line of the STARTER relay based on communication with the EMS ECU.
• Control of the immobilizer function.
• Control of the BES warning function.

Engine Start Button System: The start button system allows the driver to operate the vehicle by simply pressing the button (called SSB) instead of using a conventional key. If the driver presses the SSB with the brake pedal depressed, key fob authentication and status transfer are performed, the BES system unlocks/locks the steering column, and the engine is started on command. The driver may release the SSB once the sequence is initiated. After one positive response to the immobilizer request, the system activates the starter motor and communicates with the EMS to monitor the running engine status and stop the starter. The driver can stop the engine by briefly pressing the SSB if the vehicle is already stopped. Emergency engine stop is possible by pressing and holding the SSB or pressing it 3 times in succession if the vehicle is in RUNNING ENGINE mode. If the engine start conditions are not met when the SSB is pressed and a valid key fob is authenticated, the system unlocks the steering column and changes the terminals to ALL: another press of the SSB is required to start the engine. For vehicles equipped with the SMK system, key fob authentication requires no action by the driver. For recovery start mode or for vehicles without SMK, the driver must insert the key fob into the key fob holder.

• Control of ignition and engine start/stop by sending a signal to the IPM.
• Status display using the ON/OFF LED indicator (amber or green).

Indicator ON/OFF Status with Ignition Off

NO	Character indicator	Confirmation
1	Power indicator	Door open, tail lamps on, ACC, ignition on
2	Indicator lamp ON for 30 sec → Lamp OFF	Door closed, tail lamps off, ignition off
3	Indicator OFF	Remote LOCK, passive LOCK
4	Tail lamp dimmer on (illumination indicator)

ON/OFF Indicator Status by Ignition Key Position

NO	Ignition conditions	Power button indicator status
1	Ignition off	White LED is on
2	ALL ACC	Yellow LED on
3	IGNITION ON (engine off)	Blue LED on
4	Starting	Hold LED status before starting
5	ENGINE RUNNING	LED is off

Operation for Each Start Button Function

1. 1
   Power on / ignition on

   • The power supply state changes in the sequence OFF → ACC → ALL → OFF by pressing the button without applying the brake (or with the brake applied) inside the vehicle with the Key FOB. (However, when the transmission is not in P, the power supply switches continuously between ACC and ALL. Conversion to OFF is not possible.)
   • Ignition is started by pressing the button while depressing the brake pedal with the transmission in P/N and the Key FOB present.

   

2. 2
   Power off / ignition off

   • Ignition can be switched off while the vehicle is stationary. (The ignition OFF state is possible regardless of the position of the shift lever.)
   • The lever will be held in N, and to park, press the lever release button after turning the ignition to OFF.

   

3. 3
   How to forcibly turn off the ignition and restart the engine while driving

   • This is a method of forcibly cutting off the power supply in the event of fuel leakage when the vehicle overturns, or in an emergency (for example, accelerator pedal feedback failure).
   • The engine stops and returns to the ACC state when the button is pressed for 2 seconds or more, 3 times successfully within 3 seconds, while driving. Restart is available within the following 30 seconds regardless of the key fob. The power supply goes through the following transitions: OFF → ACC → IGN → OFF by pressing the button without pressing the brake (or with the brake pressed) inside the vehicle with the key fob. (However, when not in P, ACC↔IGN repeats. Conversion to OFF is not possible.)

   

4. 4
   Brake switch input has a 0.5 second delay function. Starting is possible with the brake pedal pressed 0.5 seconds after pressing the start button with the engine off.
5. 5
   The start button indicator (LED) illuminates according to the power supply status.

   • Power off: LED off
   • ACC power supply status: yellow LED illuminated
   • Power on: blue LED illuminated
   • During start: the previous LED remains illuminated until start
   • Initial ON state: LED OFF

   

RECOVERY DRIVING MODE

• If there is no input signal from the brake (TA specification), ACC mode must change to START by pressing the SSM button for 10 seconds.
• In case of communication problems between the EMS and CAN (EMS state), START switches to ENGINE CYCLE depending on the engine speed input.
• If one of the two SSM input lines is disconnected, power on and off is available by pressing the SSB button twice within 10 seconds (SSB LIMP HOME PRESS). The buzzer sounds when the button is pressed the first time. The power cycle is available, and the buzzer stops when the button is pressed twice within ten seconds.

Smart Key

SMK controls all functions related to:

• On/Off button (SSB) control,
• Immobilizer communication (with engine control unit to activate immobilizer),
• Authentication server (transponder validity and, in case of authentication, passive key fob option SMK),
• system integrity check,
• system diagnostics,
• Message display/buzzer control

The Smart Key Unit controls the start button of the engine start system. In the case of SMK application, "Passive Entry", "Passive Locking" and "Passive Authorization" are integrated for operations. Terminal". It collects vehicle status information from other modules (vehicle speed, alarm status, driver door open, etc.), reads inputs (for example, SSB, capacitive sensor/lock button, PARK position switch), controls outputs (for example, external room antennas), and communicates with other devices via the CAN network as well as single-wire interfaces. Diagnosis and learning of BES system components are also controlled by SMK. SMK controls functions related to "Terminal Control" by activating external relays for ACC, ALL 1 and ALL 2. This unit is also responsible for control of the STARTER relay. SMK also controls the SSB illumination and the "system status indicator", which consists of two LEDs of different colors. Key fob support is also handled by SMK. SMK reads inputs (inserted key fob, vehicle speed, relay contact status), controls outputs (relay output wires for the engine) and communicates with other devices via CAN. The internal architecture of SMK is designed so that terminal control is protected even if one or two microcontrollers fail, system inconsistency or communication interruption on the network MAY occur. If one or two controllers fail, the remaining controller disables the starter relay. The ALL1 and ALL2 terminal relays will be held in the latched state until failure, and the driver can deactivate these ALL terminals by pressing the SSB with the EMERGENCY_STOP press sequence. However, engine restart is not permitted. The state of the ACC relay depends on the failure type. The main functions of SMK are:

• Terminal control relay
• Check vehicle speed received from the ABS/ESP sensor ECU.
• SSB LED control (on, off)
• Control of the base station located in the SSB via direct serial interface.
• System consistency check to diagnose SMK failure and enter driving recovery mode.
• Provision of vehicle speed information
• On/Off button (SSB) control
• Electric starter control

Start/Stop Button (SSB) A one-step button is used by the driver to operate the vehicle. Pressing this button allows you to:

• Activation of OFF, ACC, ON and START power modes by switching to the corresponding terminals
• Starting the Engine
• Turning Off the Engine

The contact is provided by a microswitch and an emergency lamp is provided to highlight the button marking if necessary. Three colored LEDs (3) are located on the outer ring of the switch. They show the system status. They are OFF (white) / ACC (yellow) / ON (green).

BES (Engine Start Button) System Status Table. System States in Learned Mode. In learned mode, the BES system can be in 6 different states depending on the status of the terminals and the engine:

System Status	Terminal status	ENGINE STATUS
1. OFF - locked	OFF	STOP
2. OFF - unlocked	OFF	STOP
3. ACC	SOUND	STOP
4. ALL	ALL1, ALL2, ACC	STOP
5. Start	IGN1, START	Starting
6. ALL - engine	ALL1, ALL2, ACC	RUNNING (means "rotates alone")

Regarding the terminals, the system states are described in the table above. They are the same as in the system based on a mechanical ignition switch. One feature of the mechanical ignition switch system is that the BES system allows a certain transition from [OFF] to [START] without passing through [ACC] and [ALL]. SYSTEM STATES in the PRIMARY MODE: The BES system can be set to 5 different states (OFF, LOCKED, or not available in the empty mode), depending on the state of the terminals and the engine:

System Status	Terminal status	ENGINE STATUS
1. OFF - UNLOCKED	OFF	STOP
2. ACC	SOUND	STOP
3. ALL	ALL1, ALL2, ACC	STOP
4. Departure	ALL1, START with special activation model	Starting
5. ALL - engine	ALL1, ALL2, ACC	RUNNING (means "rotates alone")

Regarding the terminals, the system states are described in the table above. They are the same as in the system based on a mechanical ignition switch. One feature of the mechanical ignition switch system is that the BES system allows a certain transition from [OFF] to [START] without passing through [ACC] and [ALL].