FUNCTION OF MAIN COMPONENTS
| Component | Function | |
|---|---|---|
| Engine Stop and Start ECU | Sends either an engine stop or restart signal to the ECM according to the signals from each sensor and switch. | |
| Engine Stop and Start ECU (Backup Boost Converter) | Supplies battery voltage to help make up for the voltage drop that occurs when the engine is restarted, preventing the operation of various systems from being interrupted due to low battery voltage. | |
| Clutch Upper Switch (Clutch Start Switch Assembly) | Recognizes that the clutch pedal is not depressed and sends a signal to the engine stop and start ECU. | |
| Clutch Lower Switch (Clutch Start Switch Assembly) | Recognizes that the clutch pedal is depressed and sends a signal to the engine stop and start ECU. | |
| Neutral Position Switch | Recognizes that the shift lever is in N and sends a signal to the engine stop and start ECU. | |
| Brake Vacuum Pressure Sensor | Detects the brake booster vacuum pressure and sends a signal to the engine stop and start ECU. | |
| Hood Lock Assembly (Engine Hood Courtesy Switch) | Detects whether the hood is open or closed and sends a signal to the engine stop and start ECU. | |
| Front Door Courtesy Light Switch Assembly (Driver) | Detects whether the driver door is open or closed and sends a signal to the engine stop and start ECU via the main body ECU (multiplex network body ECU) via CAN communication. | |
| Front Seat Inner Belt Assembly (Driver) (Front Seat Belt Buckle Switch (Driver)) | Detects whether or not the driver's seat belt has been fastened, and sends a signal to the engine stop and start ECU via the main body ECU (multiplex network body ECU) via CAN communication. | |
| Air Conditioning Amplifier Assembly* | Sends an outside temperature signal and an engine restart signal to the engine stop and start ECU. | |
| Blower Switch | Sends a blower operation signal to the engine stop and start ECU. | |
| Combination Meter Assembly | Stop and Start Indicator Light |
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| Stop and Start Cancel Indicator Light |
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| Multi-information Display |
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| Ecorun Cancel Switch Assembly | Operation of the system can be canceled by pressing the ecorun cancel switch assembly. Pressing the switch again or turning the power source off and back on restores the operation of the system. | |
| Generator Control ECU Assembly | Detect the battery temperature and how much power is being charged to or discharged from the battery and sends signals to the ECM. These signals are used to protect the battery. | |
| ECM | Sends various information about engine conditions to the engine stop and start ECU. | |
| Brake Actuator Assembly (Skid Control ECU) | Sends a vehicle speed signal to the engine stop and start ECU. | |
| Airbag Sensor Assembly | Sends airbag deployment information in the event of a collision and a deceleration signal to the engine stop and start ECU. | |
| Main Body ECU (Multiplex Network Body ECU) | Sends a front door courtesy light switch signal and front seat belt buckle switch (driver) signal to the engine stop and start ECU. | |
| Power Steering ECU Assembly | Sends an electrical power steering assist signal to the engine stop and start ECU. | |
| Generator Assembly | Sends the generator assembly generation condition to the engine stop and start ECU via the ECM. | |
*: Models with air conditioning system
SYSTEM CONTROL
Operating Conditions at Engine Stop and Restart
The engine may stop if all of these conditions are detected.
| Item | Operating Condition | |
|---|---|---|
| Idle Stop | Engine Coolant Temperature | 40°C to 105°C (104°F to 221°F) |
| Outside Temperature | -5°C (23°F) or more | |
| Driver Door | Closed | |
| Brake Booster Vacuum | Sufficient brake booster vacuum | |
| Ecorun Cancel Switch Assembly | Off condition | |
| Vehicle Speed | 0 km/h (0 mph) | |
| Clutch Pedal | Released | |
| Shift Lever Position | Neutral | |
| Engine Hood | Closed | |
| Battery Voltage | 6.5 V or more at engine start. | |
| Battery Temperature | -10°C to 70°C (14°F to 158°F)*1 | |
| Battery Integrated Current*2 | When the integrated current value meets any of the following conditions:
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| Air Conditioning*5 | During "cooling down or warming up" or defrost function is not operating. | |
| Steering Operation | Not operated | |
| Engine Speed | 1250 r/min or less | |
| Driver's Seat Belt | 3 seconds or more elapse after the seat belt is fastened. | |
| Accelerator Pedal | Not depressed | |
*1: When the battery temperature becomes -15°C or lower or 75°C or higher, control is prohibited. After control is prohibited and the battery temperature rises to -10°C or higher or falls to 70°C or lower, control is performed.
*2: Regarding Battery Integrated Current
In the stop and start system, the engine stop and start ECU switches the system control mode (stop and start system control permitted/prohibited) based on the battery condition (charge/discharge condition) to protect the battery and to ensure stable engine restarting performance.
The battery charge-discharge condition is determined from the integrated current value calculated from the battery current sensor (generator control ECU assembly) signal. The integrated current value is obtained by multiplying the current (ampere) detected by the battery current sensor (generator control ECU assembly) by the time (seconds), and it is expressed in the unit A-sec. This can be measured by the Global TechStream (GTS).
The engine stop and start ECU determines the power charge based on the integrated current value and prohibits stop and start system control if the value is below the threshold, because the battery might not be able to start the engine. The threshold varies according to the battery temperature and battery charge condition.
*3: After the integrated current value becomes -6451 A-sec or less, in order to charge the battery, control is prohibited until the value becomes -5299 A-sec or more.
*4: After the integrated current value becomes -1152 A-sec or less, in order to charge the battery, control is prohibited until the value becomes 0 A-sec or more.
*5: Models with air conditioning system
The engine will restart if any of these conditions are detected.
| Item | Operating Condition | |
|---|---|---|
| Engine Restart | Brake Booster Vacuum | Insufficient brake booster vacuum |
| Air Conditioning*1/Heater |
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| Ecorun Cancel Switch Assembly | The ecorun cancel switch assembly is turned on. | |
| Heater Switch Assembly*3 | The heater switch assembly is turned on. | |
| Battery |
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| Driver's Door | The driver's door is opened. | |
| Driver's Seat Belt | The driver's seat belt is unfastened. | |
| Vehicle Speed | A vehicle speed signal is input. | |
| Clutch Pedal | The clutch pedal is depressed. | |
| DPF Warning Indicator Light | Illuminates. | |
| Steering Operation | The steering wheel is operated. | |
*1: Models with air conditioning system
*2: Models with mirror heater system
*3: Models with combustion type power heater
System Prohibit Control
For safety, battery protection, comfort and ECU learning reasons, the engine stop and start ECU prohibits stop and start system operation if any one of the following conditions is met.
| Prohibition Reason | Condition |
|---|---|
| Safety | If the engine is started with the hood open, such as when jump starting, engine restart operation cannot be ensured. Therefore, stop and start system operation will be prohibited. Operation of the system will be restored on the next trip. |
| If the driver door or hood is opened before the engine stops, stop and start system operation will be prohibited. | |
| The brake booster vacuum is insufficient. | |
| The driver seat belt is unfastened before the engine stops. | |
| The engine catalyst is being quickly warmed up. | |
| Battery Protection | If the electrical load is high and the engine is stopped for a long period of time, stop and start system operation will be prohibited. |
| The refresh charge continues for 0.5 to 1 hour, and is carried out approximately every about 20 hours or driving. While refresh charge, stop and start system operation will be disabled. | |
| When the idle stop rate becomes higher than a predetermined rate, stop and start system operation will be disabled. | |
| When the battery voltage becomes low and the battery integrated current value drops to below the threshold value, stop and start operation will be disabled. | |
| Comfort | If the air conditioning is on when the outside temperature is high and the evaporator temperature is high, stop and start system operation will be prohibited.*1 |
| If the air conditioning is on when the outside temperature is low, stop and start system operation will be prohibited.*1 | |
| If the heater is on when the outside temperature is low and the engine coolant temperature is low, stop and start system operation will be prohibited. | |
| If the front DEF switch and blower switch are on, stop and start system operation will be prohibited. | |
| If the heater switch assembly*2 is turned on, stop and start system operation will be prohibited. | |
| Engine Protection | DPF regeneration is prior to stop and start operation during DPF regeneration. |
*1: Models with air conditioning system
*2: Models with combustion type power heater
Warning Control
If any of the following operations are performed while the engine is stopped due to system control, the system will not restart the engine. The driver will be warned by a buzzer, or the engine will be regarded as stalled or will be restarted.
| Operation | Warning Control |
|---|---|
| Driver door is opened. | The engine status changes to 'stalled' or is restarted. |
| Hood is opened. | The engine status changes to 'stalled' or is restarted. |
| Shift lever is moved without depressing the clutch pedal. | Buzzer sounds and the stop and start indicator light blinks. |
| The driver seat belt is released. | The engine changes to restarted. |
FUNCTION
Settings of Stop and Start System
Using the steering pad switch assembly and the multi-information display on the combination meter assembly, the engine stop operation time due to stop and start control when the air conditioning system is on can be changed between Normal and Extended (the stop and start system has priority).
DIAGNOSIS
When the engine stop and start ECU detects a malfunction and CAN communication is normal, the engine stop and start ECU records information related to the malfunction. Furthermore, the stop and start indicator light in the combination meter assembly blinks to inform the driver that CAN communication is normal.
The engine stop and start ECU also stores Diagnostic Trouble Code (DTCs) related to malfunctions. DTCs can be read using the Global TechStream (GTS).