Nissan Qashqai J11. Manual - part 472

SYSTEM

EC9-43

< SYSTEM DESCRIPTION >

[R9M]

EC9

When the engine restart conditions are satisfied, ECM activates the engine restart relay, the engine restart
bypass control relay, and the engine restart bypass relay to restart the engine. And the DC/DC converter
boosts the voltage during cranking to protect the electrical equipment from low voltage.
After restarting the engine, the stop/start indicator lamp and the indication on the information display turn OFF.
NOTE:
• When engine restart conditions are satisfied during the electric parking brake operation, ECM performs the

engine restart after the completion of the electric parking brake operation. This may cause delay in engine
restart, compared with a usual engine restart.

• When the electric parking brake operation and engine restart occur simultaneously, the electric parking

brake activates after the completion of engine restart.

Stop/Start Readiness Condition

ECM judges stop/start system is ready when the following conditions are satisfied.

*1: Depends on the vehicle conditions.

Item

Condition

Vehicle

Stop/start OFF switch

OFF (Switch indicator: OFF)

Stop/start indicator Lamp

Not blink (No malfunction)

Door (driver side)

Seat belt (driver side)

Fastened

Driving history

Drive the vehicle at 20 km/h (12 MPH) or more after start the en-
gine with ignition switch

Passes 2 minutes or more after start the engine with ignition

switch

Gear position other than neutral is selected after restart

Drive the vehicle at 4 km/h (2.5 MPH) or more after restart

Passes 5 seconds or more after restart

Hood

Air conditioning

Automatic air condi-
tioning

Not in DEF mode

Receives Stop/start permit signal
(for details, refer to

HAC-32, "STOP/START SYSTEM : System

Description"

Manual air condi-
tioning

Not in DEF mode

ABS

System is normal

ABS not activated

ESP not activated

EPS

System is normal

Battery status

Receives Stop/start permit signal from IPDM E/R.
(for details, refer to

CHG-8, "ENERGY MANAGEMENT SYSTEM

: System Description"

Elevation

2,000 m (6,562 ft) or less

Intelligent parking assist

OFF

Engine

MIL (Malfunction indicator lamp)

Not illuminate (No malfunction)

DPF

Not regeneration

Engine coolant temperature

20 - 105

C (69 -221

Fuel temperature

C (194

F) or less

Turbocharger temperature

670

C (1238

F) or less

Starter motor

The number of starter motor operations exceeds the specified
times

High pressure fuel pump

The number of high pressure fuel pump operations exceeds the
specified times

EC9-44

< SYSTEM DESCRIPTION >

[R9M]

SYSTEM

*2: If ABS system is activated, drive the vehicle at 12 km/h (7.5 MPH) or more after stop the vehicle.

CAUTION:

• The stop/start system may be cancelled when the battery is weak or if a battery other than the stop/

start system specific battery is used.

• Even though the vehicle is in above conditions, the stop/start system may be cancelled automati-

cally.
Refer to

EC9-10, "Precaution for Stop/Start System Service"

Stop/Start Operation Condition

When the following conditions are satisfied, ECM stops the engine. And the combination meter turns ON a
stop/start indicator lamp.

NOTE:
During the operation of the stop/start system, the stop/start system continues operating even if the vehicle is
stopped by using the parking brake.

Restart Condition

When any of the following conditions is satisfied during stop/start system operating condition (gear position is
neutral), ECM restarts the engine. And the combination meter turns OFF the stop/start indicator lamp.

*: Restart timing varies according to vehicle condition. For details, refer to RELATIONSHIP BETWEEN VEHI-
CLE CONDITION AND RESTART TIMING.
NOTE:
In models with M/T, the stop/start system operates continuously even if the steering wheel is operated during
the system operating condition.

Restart Inhibit Mode

When the any of the following condition is satisfied during stop/start system operating condition, ECM inhibits
restart of the engine (go into a state in ENGINE STALL). In this case, the engine needs to be started with igni-
tion switch.

Item

Condition

Vehicle

Stop/start readiness condition

Ready

Vehicle speed

Vehicle stopped [0 km/h (0 MPH)]

Steering wheel

Not steer (steering force does not occur)

Brake booster pressure

Presence of sufficient negative pressure to a brake-
force. (Refer to

BRC-36, "BRAKE FORCE DISTRI-

BUTION FUNCTION : System Description"

Clutch pedal position

Released

Engine

Engine speed

Around idle speed (Approx. 850 rpm or less)

Transmission

Shift lever position

Neutral position

Item

Condition

Stop/start OFF switch

ON (Switch indicator: ON)

Clutch pedal position

Fully depressed

Air conditioning

Automatic air conditioning

DEF switch is pressed.

Air conditioning system cannot keep the perfor-
mance.

Manual air conditioning

Mode dial is in DEF position.

Brake booster pressure

Insufficient negative pressure for braking force

Vehicle speed

2 km/h (1.3 MPH) or more

Intelligent parking assist

Intelligent parking assist is activated.

Battery

Poor battery performance
(for details, refer to

CHG-8, "ENERGY MANAGE-

MENT SYSTEM : System Description"

SYSTEM

EC9-45

< SYSTEM DESCRIPTION >

[R9M]

EC9

*: When the condition is satisfied either door open or seat belt released, ECM transitions to the recovery wait-
ing mode (not ENGINE STALL) for approximately 5 minutes. In this case, the engine is able to start by clutch
operation.

RELATIONSHIP BETWEEN VEHICLE CONDITION AND RESTART TIMING

ECM detects clutch pedal position based on the clutch pedal position switch signal and clutch interlock switch
signal. The engine restart timing varies with gear position, vehicle speed, and clutch position.

Engine restart condition

x: Restart —: Not restart

NOTE:
If the above mentioned “Not restart” condition occurs during restart, ECM stops cranking and returns to the
stop/start system operating condition (engine stop).

ENGINE STALL ASSIST FUNCTION

The engine stall assist function allows the engine to start only with a clutch operation without operating the
ignition switch when a clutch operation is unsuccessful during vehicle start.
When an engine stall caused by a clutch operation error is detected, the stop/start system enters the recovery
waiting mode and ECM indicates the activation of engine stall assist function by illuminating the stop/start indi-
cator lamp. When the clutch pedal is depressed under this condition, the engine starts.
NOTE:
This function also operates at an engine start other than the one performed during stop/start system operation.
This function operates when the following conditions are satisfied:
• After engine warm-up.
• Vehicle stopped. (No vehicle speed input.)
• The battery is charged enough.
• No malfunctions in the engine control system and the stop/start system. (No DTC detected.)

EARLY START-UP CONTROL

ECM detects engine reverse revolution based on the crankshaft position sensor (POS) when the stop/start
system is activated and judges a piston position on engine stop to reduce the time for restarting the engine.

VOLTAGE STABILIZER FUNCTION

ECM transmits a voltage stabilizer signal to the DC/DC converter during cranking at an engine restart. The
DC/DC converter temporarily increases the voltage to prevent the electric equipment from reset due to low
voltage. The adoption of the DC/DC converter enables a stable power supply to the electric equipment con-
nected to the DC/DC converter and permits a substantial lowering of the voltage. For the electrical equipment
connected to the DC/DC converter, see “SYSTEM DIAGRAM”.
NOTE:
The brightness of the head lamps may be changed due to the voltage reduction at an engine restart because
they are not connected to the DC/DC converter.

Item

Condition

Engine hood

Opened

Driver presence

Absent: Both of the following conditions are
satisfied.
• Seat belt (driver side): Released
• Door (driver side): Open

Vehicle condition

Clutch pedal position

Vehicle

speed

Gear

position

Fully depressed

Half depressed

Released

Clutch pedal

position SW

Clutch interlock

Clutch pedal

position SW

Clutch interlock

Clutch pedal

position SW

Clutch interlock

OFF

Vehicle

stopped

Neutral

—

Except
neutral

—

Vehicle

speed oc-

curs

Neutral

Except
neutral

—

EC9-46

< SYSTEM DESCRIPTION >

[R9M]

SYSTEM

ENGINE RESTART BYPASS RELAY CONTROL

ECM controls the engine restart bypass control relay and activates
the engine restart bypass relay. When the restart conditions are sat-
isfied, ECM turns ON the engine restart bypass control relay instan-
taneously right after the restart and opens the engine restart bypass
relay. This allows a current to pass the inner resistance circuit right
after the starter motor is activated. When the starter motor is rotat-
ing, the voltage is directly supplied to the starter motor without being
passed through the inner resistance circuit in the engine restart
bypass relay because the engine restart bypass relay is closed. In
this way, ECM enables the battery voltage stabilization and reduces
the battery deterioration rate by decreasing the battery voltage drop
resulted from cranking at an engine restart.

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