i-stop CONTROL [SKYACTIV-G 1.3, SKYACTIV-G 1.5]SM2759985
i-stop CONTROL [SKYACTIV-G 1.3, SKYACTIV-G 1.5]

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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. (See Engine stop control (with Mazda M Hybrid).) (See Engine stop control (without Mazda M Hybrid).)
Engine restart control
• The engine restarts when the i-stop (engine restart control) conditions are met. (See Engine restart control (with Mazda M Hybrid).) (See Engine restart control (without Mazda M Hybrid).)
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. (See ELECTRIC AT OIL PUMP [CW6A-EL].)
Vehicle roll prevention function
• Controls the traction control solenoid valve in the DSC HU/CM to maintain or decrease brake fluid pressure. (See VEHICLE ROLL PREVENTION FUNCTION.)


Block Diagram

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Operation


Engine stop control (with Mazda M Hybrid)

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

MTX

PCM
Vehicle speed
10 km/h {6.2 mph} or less
WSPD_SEN_LF
WSPD_SEN_RF
WSPD_SEN_LR
WSPD_SEN_RR
Brake fluid pressure
Brake fluid pressure is 0.3 MPa {3 kgf/cm 2, 44 psi} or less
TR
BRK_F_P_C
Accelerator pedal
Released
APP
Clutch pedal
Released
CPP
MTX gear position
Neutral
CPP/PNP
Steering speed
15 deg/s or less
STR_ROT_SPD
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)
1 km/h {0.6 mph} or more
I-Stop_VSP
Mazda M hybrid bypass mode operation condition
Bypass mode is not operated (BYPS_STAT: Bypass Off)
BYPS_STAT
Capacitor (Mazda M hybrid) voltage
18.5 V or more
CAPA_UL_V
Capacitor (Mazda M hybrid) actual internal resistance
27 mΩ or more
CAPA_IN_R
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/cm 2, −7.22 psi} or less
(value calculated by subtracting BARO from BBP)
BBP
BARO
Door (driver's side)
Closed
DOOR_D
Bonnet
Closed *1
HOOD
Vehicle inclination angle
If i-stop control is performed (engine stop control) while driving
Within ±1.1° when level *5
Within ±7° when level *6
Not applicable
Seat belt (driver's side)
Fastened *2
SEAT_B_D
Battery condition setting
Completed
Not applicable
Steering angle sensor initial setting
Not applicable
Not applicable
Engine coolant temperature
55—110 °C {131—230 °F} *5
Below 20 °C {68 °F} *6
ECT
Intake air temperature
100 °C {212 °F} or less
IAT
Altitude
2,000 m or less (BARO: 79.0 kPa {0.806 kgf/cm 2, 11.5 psi} or more)
BARO
System condition
i-stop related part DTCs are not recorded
Not applicable
ISG temperature
100 °C {212 °F} or less
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 *2
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
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 less
(Cabin temperature control by A/C is normally performed)
Not applicable
A/C temperature (with full-auto air conditioner system)
Setting other than MIN *3
Not applicable
Ambient temperature
−10―50 °C {14—122 °F}
Not applicable
Warm-up operation condition (with manual air conditioner system)
Ambient temperature is 10 °C {50 °F} or more or engine coolant temperature is 60 °C {140 °F} or more
ECT
Cold condition (with manual air conditioner system)
Ambient temperature is 20 °C {68 °F} or less or evaporator temperature is specified value or less
Not applicable
Cold condition (with full-auto air conditioner system)
Ambient temperature is 4 °C {39 °F} or more or evaporator temperature is 12 °C {54 °F} or less
Not applicable
MODE dial
Except DEFROSTER
Not applicable
Airflow volume control dial (with full-auto air conditioner system)
OFF *4
Not applicable
System condition
i-stop related part DTCs are not recorded
Not applicable

*1:If the engine is started with the bonnet open, i-stop is inhibited until the engine is stopped.
*2:If the seat belt is unfastened while the vehicle is stopped, i-stop is inhibited until a vehicle speed record is input once.
*3:When the A/C set temperature is set to MAX, the PCM may inhibit the i-stop control.
*4: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.
*5:without EGR cooler.
*6:with EGR cooler.
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) (SKYACTIV-G 1.5 (with 4-2-1 exhaust system))
• Intake valve timing retard is performed for engine restart by i-stop control.


Engine restart control (with Mazda M Hybrid)

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

MTX

PCM
Vehicle speed
If i-stop control is performed (engine stop control) while vehicle is stopped
1 km/h {0.6 mph} or more
WSPD_SEN_LF
WSPD_SEN_RF
WSPD_SEN_LR
WSPD_SEN_RR
Vehicle speed
If i-stop control is performed (engine stop control) while driving
11 km/h {6.8 mph} or more
WSPD_SEN_LF
WSPD_SEN_RF
WSPD_SEN_LR
WSPD_SEN_RR
Accelerator pedal
Accelerator pedal is depressed
APP
Clutch pedal *1
• Brake pedal depressed and vehicle stopped → shift operation performed → brake pedal released
• Brake pedal depressed and vehicle stopped → shift operation performed → clutch pedal released
• Brake pedal depressed and vehicle stopped → brake pedal released → shift operation performed
• Brake pedal depressed and vehicle stopped for 1 s or more → brake pedal released → brake pedal depressed
BRK_F_P_C
CPP
i-stop OFF switch
ON
I-Stop_OFF
Battery charge condition
65% or less
BATT_SOC
Power brake unit vacuum
−47.8 kPa {−0.487 kgf/cm 2, −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
― Shift lever position: Neutral
SEAT_B_D
DOOR_D
TR
CPP/PNP
Engine stop period by i-stop
If i-stop control is performed (engine stop control) while vehicle is stopped
120 s or more
Not applicable
Engine coolant temperature
55 °C {131 °F} or less *2
Below 20 °C {68 °F} *3
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
Climate control unit
A/C request (with full-auto air conditioner system)
Yes
STOP_ST
A/C set temperature (with full-auto air conditioner system)
Set to MIN
Not applicable
MODE dial
DEFROSTER
Not applicable
System condition
An i-stop related part DTC is recorded
Not applicable

*1:Only the clutch pedal depression is not operable. If any of the conditions is met, the PCM determines that the driver is attempting to accelerate the vehicle from the stop.
*2:without EGR cooler.
*3:with EGR cooler.
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 CKP sensor and fuel injection is enabled to those cylinders which are identified first as being stopped in the expansion stroke.


Engine stop control (without Mazda M Hybrid)

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 2.3 MPa {23 kgf/cm 2, 334 psi} or more while in D or M position
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
STR_AB_EST
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
i-ELOOP bypass mode operation condition
Bypass mode is not operated (BYPS_STAT: Bypass Off)
BYPS_STAT
Capacitor (i-ELOOP) 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/cm 2, −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 {131—230 °F}
ECT
Intake air temperature
100 °C {212 °F} or less
IAT
Altitude
2,000 m {6561 ft} or less (BARO: 79.0 kPa {0.806 kgf/cm 2, 11.5 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 air conditioner system)
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 air conditioner system)
Setting other than MIN *5
Not applicable
Ambient temperature
−10―50 °C {14—122 °F}
Not applicable
Warm-up operation condition (with manual air conditioner system)
Ambient temperature is 10 °C {50 °F} or more or engine coolant temperature is 60 °C {140 °F} or more
ECT
Cold condition (with manual air conditioner system)
Ambient temperature is 20 °C {68 °F} or less or evaporator temperature is specified value or less
Not applicable
Cold condition (with full-auto air conditioner system)
Ambient temperature is 4 °C {39 °F} or more or evaporator temperature is 12 °C {54 °F} or less
Not applicable
MODE dial
Except DEFROSTER
Not applicable
Airflow volume control dial (with full-auto air conditioner system)
OFF *6
Not applicable
System condition
i-stop related part DTCs are not recorded
Not applicable
DSC HU/CM *4
Operation request from TCM
Hill Launch Assist (HLA) control request signal from TCM 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. 0.45 MPa {4.6 kgf/cm 2, 65 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 bonnet 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:Even if the DSC HU/CM i-stop permit conditions are not met on a flat road surface and downslope, the i-stop function operates. After the i-stop permit condition met on an up slope (slope of 2% or more), the i-stop function operates.
*5:When the A/C set temperature is set to MAX, the PCM may inhibit the i-stop control.
*6: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.
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) (SKYACTIV-G 1.5 (with 4-2-1 exhaust system))
• 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.
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Engine restart control (without Mazda M Hybrid)

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/cm 2, 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
• Brake fluid pressure 4.5 MPa {46 kgf/cm 2, 653 psi} or less: Determined by clutch pedal depression amount *1
• Brake fluid pressure 4.5 MPa {46 kgf/cm 2, 653 psi} or more: Clutch pedal depressed → released *2
BRK_F_P_C
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
PCM
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
Battery charge condition
65% or less
BATT_SOC
Power brake unit vacuum
−47.8 kPa {−0.487 kgf/cm 2, −6.93 psi} or more
(value calculated by subtracting BARO from BBP)
BBP
BARO
Driver not seated (except for European (L.H.D U.K.) specs.)
• All the following conditions are met:
― Seat belt (driver's side): Not fastened
― Door (driver's side): Open
― Bonnet: Open
― P or N position *3
• All the following conditions are met:
― Seat belt (driver's side): Not fastened
― Door (driver's side): Open
― Neutral *3
SEAT_B_D
DOOR_D
TR
CPP/PNP
Driver not seated (European (L.H.D U.K.) specs.)
• All the following conditions are met:
― Seat belt (driver's side): Not fastened
― Door (driver's side): Open
― Bonnet: Open
― P or N position *4
• All the following conditions are met:
― Seat belt (driver's side): Not fastened
― Door (driver's side): Open
― Neutral *4
SEAT_B_D
DOOR_D
TR
CPP/PNP
Engine stop period by i-stop
120 s or more
Not applicable
Engine coolant temperature
55 °C {131 °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
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
Not applicable
Climate control unit
A/C request (with full-auto air conditioner system)
Yes
STOP_ST
A/C set temperature (with full-auto air conditioner system)
Set to MIN
Not applicable
MODE dial
DEFROSTER
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:Engine restarts when the clutch pedal is depressed.
*2:Engine does not restart when the clutch pedal is depressed. When the clutch pedal is released from the depressed position, the PCM determines that the driver intends to accelerate the vehicle from the stop and restarts the engine.
*3:Except for JM6 DJ2***** 450001— and 3MD DJ2***** 400001—.
*4:Except for JMZ DJ6***** 350001— .
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 CKP 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.
― i-ELOOP control (i-stop mode) (with i-ELOOP)
• During engine restarting by i-stop, the power supply source is divided between the battery and capacitor (i-ELOOP) to assure a supply of power to the vehicle’s electrical devices.
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