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Nissan Juke F15. Manual - part 454

SYSTEM

EC-629

< SYSTEM DESCRIPTION >

[MR EXCEPT FOR NISMO RS MODELS]

DIRECT INJECTION GASOLINE SYSTEM

P2122
P2123
P2127
P2128
P2138

Accelerator pedal position
sensor

—

The ECM controls the electric throttle con-
trol actuator in regulating the throttle open-
ing in order for the idle position to be within
+10 degrees.
The ECM regulates the opening speed of
the throttle valve to be slower than the nor-
mal condition.
So, the acceleration will be poor.

P2162

Vehicle speed sensor

—

P2263

Turbocharger system

—

P2562
P2566

Electric wastegate control
valve position sensor

—

The ECM stops the electric wastegate actu-
ator control, engine can not be super-
charged driving.The ECM requlates engine
power limiter and EGR Off.

P2563

Electric wastegate control
valve position sensor

—

P2564

Electric wastegate control
valve position sensor

—

P2565

Electric wastegate control
valve position sensor

—

P26A3
P26A5
P26A6
P26A7

Multi-way control valve

—

• When detecting a malfunction with the

valve closed, ECM fully opens the valve.

• When detecting a malfunction with the

valve opened, ECM maintains valve an-
gle.

• When detecting a malfunction in sensor,

ECM fully opens the valve.

• ECM limits the engine output depending

on malfunctions.

DTC

No.

Detected items

Vehicle behavior

Pattern

Others

EC-630

< SYSTEM DESCRIPTION >

[MR EXCEPT FOR NISMO RS MODELS]

SYSTEM

DIRECT INJECTION GASOLINE SYSTEM : System Diagram

INFOID:0000000012198201

DIRECT INJECTION GASOLINE SYSTEM : System Description

INFOID:0000000012198202

INPUT/OUTPUT SIGNAL CHART

JPBIA5479GB

SYSTEM

EC-631

< SYSTEM DESCRIPTION >

[MR EXCEPT FOR NISMO RS MODELS]

*1: This sensor is not used to control the engine system under normal conditions.
*2: CVT models
*3: M/T models
*4: ECM determines the start signal status by the signals of engine speed and battery voltage.

SYSTEM DESCRIPTION

The adoption of the direct fuel injection method enables more accurate adjustment of fuel injection quantity by

injecting atomized high-pressure fuel directly into the cylinder. This method allows high-powered engine, low

fuel consumption, and emissions-reduction.

The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of

time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the

ECM memory. The program value is preset by engine operating conditions. These conditions are determined

by input signals (for engine speed, intake air, fuel rail pressure and boost) from the crankshaft position sensor,

camshaft position sensor, mass air flow sensor, fuel rail pressure sensor and the turbocharger boost sensor.

VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION

In addition, the amount of fuel injected is compensated to improve engine performance under various operat-

ing conditions as listed below.

• During warm-up

• When starting the engine

• During acceleration

• Hot-engine operation

• When selector lever position is changed from N to D (CVT models)

• High-load, high-speed operation

• During deceleration

• During high engine speed operation

Sensor

Input signal to ECM

ECM func-

tion

Actuator

Crankshaft position sensor (POS)

Engine speed

Fuel injection
& mixture ra-
tio control

Fuel injector

Camshaft position sensor (PHASE)

Camshaft position

Mass air flow sensor

Amount of intake air

Intake air temperature sensor 1

Intake air temperature

Engine coolant temperature sensor

Engine coolant temperature

Air fuel ratio (A/F) sensor 1

Density of oxygen in exhaust gas

Fuel rail pressure sensor

Fuel rail pressure

Throttle position sensor

Throttle position

Accelerator pedal position sensor

Accelerator pedal position

Battery

Battery voltage

Knock sensor

Engine knocking condition

Heated oxygen sensor 2

Density of oxygen in exhaust gas

Transmission range switch

Gear position

Park/neutral position (PNP) switch

G sensor

Inclination angle

Turbocharger boost sensor

Turbocharger boost

ABS actuator and electric unit (control unit)

CAN communi-
cation

• Wheel speed signal
• VDC/TCS operation command

BCM

CAN communi-
cation

A/C ON signal

Combination meter

CAN communi-
cation

Vehicle speed signal

EC-632

< SYSTEM DESCRIPTION >

[MR EXCEPT FOR NISMO RS MODELS]

SYSTEM

FUEL INJECTION CONTROL

Stratified-charge Combustion

Stratified-charge combustion is a combustion method which enables extremely lean combustion by injecting

fuel in the latter half of a compression process, collecting combustible air-fuel around the spark plug, and form-

ing fuel-free airspace around the mixture.

Right after a start with the engine cold, the catalyst warm-up is accelerated by stratified-charge combustion.

Homogeneous Combustion

Homogeneous combustion is a combustion method that fuel is injected during intake process so that combus-

tion occurs in the entire combustion chamber, as is common with conventional methods.

As for a start except for starts with the engine cold, homogeneous combustion occurs.

MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)

The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission control.

The three way catalyst (manifold) can better reduce CO, HC and NOx emissions. This system uses A/F sen-

sor 1 in the exhaust manifold to monitor whether the engine operation is rich or lean. The ECM adjusts the

injection pulse width according to the sensor voltage signal. For more information about A/F sensor 1, refer to

EC-614, "Air Fuel Ratio (A/F) Sensor 1"

. This maintains the mixture ratio within the range of stoichiometric

(ideal air-fuel mixture).

This stage is referred to as the closed loop control condition.

Heated oxygen sensor 2 is located downstream of the three way catalyst (manifold). Even if the switching

characteristics of A/F sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal from heated

oxygen sensor 2.

• Open Loop Control

The open loop system condition refers to when the ECM detects any of the following conditions. Feedback

control stops in order to maintain stabilized fuel combustion.

- Deceleration and acceleration

- High-load, high-speed operation

- Malfunction of A/F sensor 1 or its circuit

- Insufficient activation of A/F sensor 1 at low engine coolant temperature

- High engine coolant temperature

- During warm-up

- After shifting from N to D (CVT models)

- When starting the engine

MIXTURE RATIO SELF-LEARNING CONTROL

The mixture ratio feedback control system monitors the mixture ratio signal transmitted from A/F sensor 1.

This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to the theoret-

ical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as originally

designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes dur-

ing operation (i.e., fuel injector clogging) directly affect mixture ratio.

Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is

then computed in terms of “injection pulse duration” to automatically compensate for the difference between

the two ratios.

“Fuel trim” refers to the feedback compensation value compared against the basic injection duration. Fuel trim

includes “short-term fuel trim” and “long-term fuel trim”.

“Short term fuel trim” is the short-term fuel compensation used to maintain the mixture ratio at its theoretical

value. The signal from A/F sensor 1 indicates whether the mixture ratio is RICH or LEAN compared to the the-

oretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an increase in

fuel volume if it is lean.

PBIB2793E

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