i-stop CONTROL [SKYACTIV-G 2.0, SKYACTIV-G 2.5]

id0140g2008900


Outline

•  When the vehicle is stopped such as at a stop light, the i-stop control stops/starts the engine automatically to improve fuel economy and reduce exhaust gas and idling noise.
•  The PCM determines whether to permit/inhibit i-stop control based on the signal from each input part and CAN communication.
•  The i-stop control includes the engine stop control, engine restart control, electric AT oil pump driver control, and hill launch assist functions.

Control Table

Control name

Control outline
Engine stop control
•  The engine is stopped when the i-stop (engine stop control) conditions are met.
Engine restart control
•  The engine restarts when the i-stop (engine restart control) conditions are met.
Electric AT oil pump driver control
•  Drives the electric AT oil pump to assure line pressure during an engine stop by the i-stop control.
Hill launch assist function
•  Controls the traction control solenoid valve in the DSC HU/CM to maintain or decrease brake fluid pressure.


Block Diagram

am6zzn00003011

Operation


Engine stop control

i-stop (engine-stop control) permit condition
•  The conditions to stop the engine by the i-stop control are as follows:

Determination module

Determination item

Determination condition

Applicable PID

ATX

MTX
PCM
Vehicle speed
0 km/h {0 mph}
3 km/h {2 mph} or less
WSPD_SEN_LF
WSPD_SEN_RF
WSPD_SEN_LR
WSPD_SEN_RR
Brake pedal
Brake pedal is depressed while in D or M position
Not applicable
TR
BPA
Brake fluid pressure
Brake fluid pressure is 1.35 MPa {13.8 kgf/cm2, 196 psi} or more while in D or M position (perform correction according to vehicle inclination angle)
Not applicable
TR
BRK_F_P_C
Accelerator pedal
Released
←
APP
Clutch pedal
Not applicable
Released
CPP
MTX gear position
Not applicable
Neutral
CPP/PNP
Vehicle conditions
Vehicle is stopped in D position*1
Not applicable
TR
Steering speed
15 deg/s or less
←
STR_ROT_SPD
Steering angle
Within 65° of center to left and right
(After EPS control module learns center value)
Not applicable
Not applicable
Steering torque
1.1 N·m {11 kgf·cm, 9.7 in·lbf} or less
←
STR_TRQ_S_M
i-stop OFF switch
OFF
←
I-Stop_OFF
Vehicle speed history
(After engine started and driven once)
3 km/h {2 mph} or more
4 km/h {2.5 mph} or more
I-Stop_VSP
DC-DC converter (i-ELOOP) output current
25 A or less
←
DCDC_OUT_I
i-ELOOP bypass mode operation condition
Bypass mode is not operated (BYPS_STAT: Bypass Off)
←
BYPS_STAT
Capacitor voltage
14 V or more
←
DCDC_IN_V
Battery charge condition
65.72 % or more
←
BATT_SOC
Battery fluid temperature
0—70 °C {32—158 °F}
←
BATT_TEMP
Battery voltage
11.2 V or more
←
BATT_V
Power brake unit vacuum
−49.8 kPa {−0.508 kgf/cm2, −7.22 psi} or less
(value calculated by subtracting BARO from BBP)
←
BBP
BARO
Door (driver's side)
Closed
←
DOOR_D
Bonnet
Closed *2
←
HOOD
Vehicle inclination angle
Within ±7° when level (LON_ACCL_C: within ±0.121 G)
Not applicable
LON_ACCL_C
Seat belt (driver's side)
Fastened*3
←
SEAT_B_D
Battery condition setting
Completed
←
Not applicable
Steering angle sensor initial setting
Completed
Not applicable
Not applicable
Engine coolant temperature
55—110 °C {55—230 °F}
←
ECT
Intake air temperature
100 °C {212 °F} or less
←
IAT
Altitude
1,800 m or less (BARO: 81.5 kPa {0.831 kgf/cm2, 11.8 psi} or more)
←
BARO
System condition
i-stop related part DTCs are not recorded
←
Not applicable
Start stop unit
+B (ROOM fuse) input
Yes
←
VPWR_B1
IG1 input
Yes
←
VPWR_IG1
ACC input
Yes
←
VPWR_ACC
IG1 output
Yes
←
RELAY_IG1
ACC output
Yes
←
RELAY_ACC
Push button
Not pressed
←
SSB_1
SSB_2
Door (all)
Closed
←
DOOR_ALL
Trunk (4SD)/Liftgate (5HB)
Closed
←
TRUNK
Seat belt (driver's side)
Fastened*3
←
SEAT_B_D
Engine start
Engine was started by operating push button with key inside cabin (engine started first time)
←
Not applicable
Engine rotation speed
300 rpm or more is maintained after engine started
←
Not applicable
System condition
i-stop related part DTCs are not recorded
←
Not applicable
TCM
TCM detection condition
All met (I-Stop_EST: On)
Not applicable
I-Stop_EST
Panic stop
Brake pedal was not depressed suddenly within 4 s
Not applicable
Not applicable
TFT
20―117 °C {68—242 °F}
Not applicable
TFT
Gear position
Not in 2nd gear fixed mode
Not applicable
Not applicable
System condition
i-stop related part DTCs are not recorded
Not applicable
Not applicable
Climate control unit
Cabin temperature (with full-auto A/C)
Difference between target cabin temperature and actual cabin temperature is a certain value or less
(Cabin temperature control by A/C is normally performed)
←
Not applicable
A/C temperature (with full-auto A/C)
Setting other than MAX/MIN*4
←
Not applicable
Ambient temperature
-10―50 °C {14—122 °F}
←
Not applicable
Warm-up operation condition (with manual A/C)
Ambient temperature is 10 °C {50 °F} or more and engine coolant temperature is 60 °C {140 °F} or more
←
ECT
Cold condition (with manual A/C)
Ambient temperature is 29 °C {84 °F} or less and evaporator temperature is 9 °C {48 °F} or less
←
Not applicable
Cold condition (with full-autol A/C)
Ambient temperature is 4 °C {39 °F} or more or evaporator temperature is 12 °C {54 °F} or less
←
Not applicable
DEFROSTER switch (with full-auto A/C)
OFF
←
DEF_SW
MODE dial (with manual A/C)
Except DEFROSTER
←
Not applicable
Airflow volume control dial (with full-auto air conditioner system)
Except MAX setting*5
←
Not applicable
Humidity
Windshield fogging judgment is standard or more*6
←
Not applicable
System condition
i-stop related part DTCs are not recorded
←
Not applicable
DSC HU/CM
Operation request from PCM
Hill Launch Assist (HLA) control request signal from PCM is received
Not applicable
Not applicable
Wheel speed (4 wheels)
0 km/h {0 mph}
Not applicable
WSPD_SEN_LF
WSPD_SEN_RF
WSPD_SEN_LR
WSPD_SEN_RR
Brake pedal
Brake pedal is depressed
Not applicable
BRAKE_SW
Brake fluid pressure
Approx. 0.5 MPa {5 kgf/cm2, 73 psi} or more
Not applicable
BRK_F_P_C
Accelerator pedal
Released
Not applicable
APP
System condition
i-stop related part DTCs are not recorded
Not applicable
Not applicable

*1  :After the vehicle is stopped, the engine stops if the gear is shifted to N position. In addition, if the gear is shifted to P position after the vehicle is stopped in D position, the engine stop condition by the i-stop control is maintained.
*2  :If the engine is started with the hood open, i-stop is inhibited until the engine is stopped.
*3  :If the seat belt is unfastened while the vehicle is stopped, i-stop is inhibited until a vehicle speed record is input once.
*4  :When the A/C set temperature is set to MAX, the PCM may inhibit the i-stop control.
*5  :When all of the other i-stop permit conditions related to the climate control unit are met even if the airflow volume control dial is on, the i-stop control is permitted.
*6  :The windshield fogging judgment is performed by adding the correction value calculated from each signal to the signal from the humidity sensor.
i-stop (engine stop control)
•  When the i-stop (engine stop control) permit conditions are met, the PCM stops the engine based on the following controls:
―  Fuel injection control (fuel cut)
•  Engine speed is reduced by the fuel cut.
―  Drive-by-wire control (throttle valve open/closed)
•  By adjusting the throttle valve opening angle, the engine speed is reduced and the pumping loss is used to stop the engine.
―  Electric variable valve timing control (intake valve timing retard)
•  Intake valve timing retard is performed for engine restart by i-stop control.
―  Generator output control (generator load)
•  Engine speed is reduced by lowering the generator load.
am6zzn00003012


Engine restart control

i-stop (engine restart control) conditions
•  Conditions for restarting the engine during i-stop control (engine stopped) are as follows:

Detection module

Detection item

Determination conditions

PID

ATX

MTX
PCM
Vehicle speed
1 km/h {0.6 mph} or more
4 km/h {2.5 mph} or more
WSPD_SEN_LF
WSPD_SEN_RF
WSPD_SEN_LR
WSPD_SEN_RR
Brake pedal
•  Brake pedal is released → depressed while in P or N position
•  Brake pedal is released while in D or M position
Not applicable
TR
BPA
Brake fluid pressure
Brake fluid pressure is 0.35 MPa {3.6 kgf/cm2, 51 psi} or less while in D or M position
Not applicable
TR
BRK_F_P_C
Accelerator pedal
Accelerator pedal is depressed while in D or M position
Not applicable
TR
APP
Clutch pedal
Not applicable
Depressed
CPP
Steering torque
4.0 N·m {41 kgf·cm, 35 in·lbf} or more while in D or M position
Not applicable
STR_TRQ_S_M
Steering angle
70° or more from center while in D or M position
(After EPS control module learns center value)
Not applicable
Not applicable
Shift operation
Operated from P or N position to D, M, or R position
Not applicable
TR
i-stop OFF switch
ON
←
I-Stop_OFF
DC-DC converter (i-ELOOP) output current
30 A or more
←
DCDC_OUT_I
Battery charge condition
65% or less
←
BATT_SOC
Power brake unit vacuum
−47.8 KPa {−0.487 kgf/cm2, −6.93 psi} or more
(value calculated by subtracting BARO from BBP)
←
BBP
BARO
Driver not seated
•  All the following conditions are met:
―  Seat belt (driver's side): Not fastened
―  Door (driver's side): Open
―  P or N position
•  All the following conditions are met:
―  Seat belt (driver's side): Not fastened
―  Door (driver's side): Open
―  Neutral
SEAT_B_D
DOOR_D
TR
CPP/PNP
Engine stop period by i-stop
120 s or more
←
Not applicable
Engine coolant temperature
53 °C {127 °F} or less
←
ECT
System condition
An i-stop related part DTC is recorded
←
Not applicable
Start stop unit
+B (ROOM fuse) input
No
←
VPWR_B1
Remote transmitter authorization
When engine restart by remote transmitter authorization is requested
•  Any door is open without remote transmitter left in vehicle
•  Remote transmitter is outside of vehicle after any door is opened
←
Not applicable
System condition
An i-stop related part DTC is recorded
←
Not applicable
TCM
Gear position
Not in 2nd gear fixed mode
Not applicable
Not applicable
TFT
20 °C {68 °F} or less, or 117°C {243 °F} or more
Not applicable
TFT
Vehicle speed
3 km/h {2 mph} or more
Not applicable
WSPD_SEN_LF
WSPD_SEN_RF
WSPD_SEN_LR
WSPD_SEN_RR
System condition
An i-stop related part DTC is recorded
←
Not applicable
Climate control unit
Cabin temperature (with full-auto air conditioner system)
Difference between target cabin temperature and actual cabin temperature is a certain value or more
(Cabin temperature control by A/C is normally performed)
←
STOP_ST
A/C set temperature (with full-auto air conditioner system)
•  If any one of the following conditions is met:
―  A/C switch: Turned ON and MAX COLD setting
―  MAX HOT setting
←
Not applicable
Ambient temperature
-10 °C {14 °F} or less, or 50 °C {122 °F} or more
←
Not applicable
DEFROSTER switch (with full-auto A/C)
ON
←
DEF_SW
MODE dial (with manual A/C)
DEFROSTER
←
Not applicable
Airflow volume control dial (with full-auto air conditioner system)
MAX setting
←
Not applicable
Humidity
Windshield fogging judgment is standard or less*3
←
Not applicable
System condition
An i-stop related part DTC is recorded
←
Not applicable
DSC HU/CM
System condition
An i-stop related part DTC is recorded
Not applicable
Not applicable

*1  :The windshield fogging judgment is performed by adding the correction value calculated from each signal to the signal from the humidity sensor.
i-stop (engine restart control)
•  When the i-stop (engine restart control) conditions are met, the PCM restarts the engine by the following controls:
―  Fuel injection control (from first time, fuel injection to specific cylinders (expansion stroke)
•  Fuel is injected to cylinders which are determined to be stopped at the expansion stroke. During i-stop control (engine stop), cylinders are identified based on the signal from the crankshaft position sensor and fuel injection is enabled to those cylinders which are identified first as being stopped in the expansion stroke.
―  DC-DC converter control
•  When the engine is restarted by the i-stop control, the battery voltage is decreased to operate the starter by supplying power from the battery. When the starter operates, the supply voltage for electronic devices is increased by the DC-DC converter.
am3uun00001956


Indicator illumination request

•  The PCM sends an i-stop indicator light (green)/i-stop warning light (amber) illumination or flash request to the instrument cluster according to the vehicle conditions.
•  The i-stop indicator light (green)/i-stop warning light (amber) illumination/flash request conditions are as follows:

IS: Engine stop by i-stop control
IR: Engine restart by i-stop control
×: Applicable
—: Not applicable

Vehicle condition

Vehicle condition

i-stop indicator light (green)/i-stop warning light (amber) display

Indicator (other)

Buzzer

Illumination on

Flash (0.5 s)

Illumination off

Illumination on/ Flash
Driving
IS conditions not met
—
—
—
×
—
—
IS conditions met*7
—
Green (Except for european (L.H.D. U.K.) specs.)/
— (European (L.H.D. U.K.) specs.)
—
— (Except for european (L.H.D. U.K.) specs.)/
× (European (L.H.D. U.K.) specs.)
—
—
Vehicle parked
IS conditions not met*7
Idle
—
Green*1(Except for european (L.H.D. U.K.) specs.)
—
—
—
—
—
×
—
—
IS conditions met*7
IS
Green
—
—
—
—
During IS
IS conditions met*7
IS
Green
—
—
—
—
IS continues normally
ATX
When the following conditions are met:
•  Brake depressed
•  D or M position (except 2nd gear fixed mode)
•  Steering angle less than 70°C {158°F} and steering torque less than 4.0 N·m {41 kgf·cm, 35 in·lbf}
When the following conditions are met:
•  Brake released
•  D or M position (except 2nd gear fixed mode) →N position
•  D or M position (except 2nd gear fixed mode) →N position →P position
IS continues
Green
—
—
—
—
MTX
Clutch pedal depressed→Clutch pedal is released while engine is cranking to restart by i-stop control
IS continues*10
During IS
IR request (driver's operation)
Engine start by key operation
IR
—
—
×*2
—
—
ATX
•  Brake pedal released → depressed while in P or N position
•  Brake pedal released while in D position or M position
•  Accelerator pedal depressed while in D or M position
•  Brake fluid pressure is 0.35 MPa {3.6 kgf/cm2, 51 psi} or less in D position or M position
•  Steering torque is 4.0 N·m {41 kgf·cm, 35 in·lbf} or more in D position or M position
•  Steering angle (D or M position (except 2nd gear fixed mode)): -70° or less or 70° or more
•  Shift operation
―  When changed to the M position (except 2nd gear fixed mode)
―  P or N position →D or M or R position
MTX
•  Clutch pedal depressed
When the following conditions are met:
•  Seat belt (driver): Not fastened
•  Door (driver): Open
•  P or N position (ATX)
•  Neutral position (MTX)
IR (Except for european (L.H.D. U.K.) specs.)/
Engine stall (European (L.H.D. U.K.) specs.)
— (Except for european (L.H.D. U.K.) specs.)/
Amber (European (L.H.D. U.K.) specs.)
—
×*2 (Except for european (L.H.D. U.K.) specs.)/
— (European (L.H.D. U.K.) specs.)
— (Except for european (L.H.D. U.K.) specs.)/
Same illumination as normal engine stall condition (European (L.H.D. U.K.) specs.)
— (Except for european (L.H.D. U.K.) specs.)/
0.25 s intervals for 3 s (European (L.H.D. U.K.) specs.)
During IS
Switches to unsafe condition (driver’s operation)
Door (driver) open
IS continues
Green
—
—
—
0.25 s intervals
When the following conditions are met:
•  Seat belt (driver): Not fastened
•  Door (driver): Open
•  D or M position (except 2nd gear fixed mode) (ATX)
•  In gear (MTX)
Engine stall
Amber
—
—
Same illumination as normal engine stall condition
0.25 s intervals for 3 s
Bonnet open
MTX
In gear
IS continues
—
Green (0.25 s)
—
—
—
IR request (vehicle request)
Any of the following conditions are met:
•  A/C request
•  Battery charge 65 % or less
•  Defroster switch on
•  Engine stop time by the i-stop control: 120 s or more
IR
—
—
×*2 (Except for european (L.H.D. U.K.) specs.)/
×*11 (European (L.H.D. U.K.) specs.)
—
—
Any of the following conditions are met:
•  Vehicle speed: 1 km/h {0.6 mph} or more (ATX)
•  Vehicle speed: 4 km/h {2.5 mph} or more (MTX)
•  Power brake unit vacuum reduced
IR
—
—
—
—
•  Remote transmitter out of vehicle
IR*6
—
—
KEY warning light (red) flashing
Start stop unit normal buzzer
IR not functional
•  Cranking for 3 s or more when engine is restarted
Engine stall
Amber
—
—
Same illumination as normal engine stall condition
—
IS permit/inhibit implement
•  i-stop OFF switch on (long pressed for 0.5 s or more)
IS not authorized*8
Amber*3
—
—
—
Beep sound
1 time
•  i-stop OFF switch off (long pressed for 0.5 s or more)
IS authorized
—
—
×*4
—
Beep sound
1 time
System malfunction
IS not authorized
—
Amber*5
—
×*9
—

*1  :Changes illumination to IS when the conditions are met for driver operation (brake pedal force).
*2  :No flashing, turns off when the engine restarts.
*3  :Illuminates according to the i-stop OFF switch operation (long-press for 0.5 s or longer).
*4  :Turns off according to the i-stop OFF switch operation (long-press for 0.5 s or longer).
*5  :It may illuminate in amber when communication between PCM is cut.
*6  :Only when the advanced key is outside of the vehicle with the doors other than driver's door open.
*7  :The i-stop (engine-stop control) permit conditions differ depending on the driving condition. (See i-stop INDICATOR LIGHT (GREEN) [SKYACTIV-G 2.0, SKYACTIV-G 2.5].)
*8  :If during engine stop by i-stop control, engine restarted by i-stop control.
*9  :If there is a battery related malfunction, the master warning light illuminates.
*10  :If the clutch pedal depressed and then it is released while the engine is cranking to restart by the i-stop control, engine stop by the i-stop control continues. If the same operation is repeated several times, the engine will stall.
*11  :Flashing before the engine restarts, turns off when the engine restarts.