Nissan Pathfinder (2010 year). Manual - part 303

 

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Nissan Pathfinder (2010 year). Manual - part 303

 

 

EC-516

< FUNCTION DIAGNOSIS >

[VK56DE]

ENGINE CONTROL SYSTEM

1.

Body ground (view with air cleaner 
case removed)

2.

Body ground (view with battery re-
moved)

3.

No.1 ignition coil

4.

Engine ground

5.

Mass air flow sensor (with intake air 
temperature sensor)

6.

IPDM E/R

7.

Battery

8.

Radiator hose

9.

Camshaft position sensor (PHASE)

AWBIA0081ZZ

2010 Pathfinder

ENGINE CONTROL SYSTEM

EC-517

< FUNCTION DIAGNOSIS >

[VK56DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

10. Electric throttle control actuator 

(view with intake air duct removed)

11. Electronic throttle control actuator 

harness connector (view with intake 
air duct removed)

12. Cooling fan motor harness connec-

tor

: Vehicle front

AWBIA0082ZZ

2010 Pathfinder

EC-518

< FUNCTION DIAGNOSIS >

[VK56DE]

ENGINE CONTROL SYSTEM

1.

EVAP canister purge volume control 
solenoid valve (view with engine 
cover removed)

2.

EVAP service port 

3.

Crankshaft position sensor (POS) 
(view from under vehicle)

4.

Engine oil pan 

5.

Condenser-1

6.

Brake fluid reservoir

7.

Fuel filler pipe (top of frame view)

8.

EVAP control system pressure sen-
sor

9.

EVAP canister vent control valve

10. EVAP canister

11. Drain filter

12. Refrigerant pressure sensor

13. Intake valve timing control position 

sensor (bank 2) (view with engine 
cover and intake air duct removed)

14. Intake valve timing control position 

sensor (bank 1) 

15. Intake valve timing control solenoid 

valve (bank 2) (view with engine cov-
er and intake air duct removed)

16. Drive belt

17. Radiator hose (view with engine cov-

er and intake air duct removed)

18

Intake valve timing control solenoid 
valve (bank 1) 

: Vehicle front

ALBIA0369ZZ

1.

Knock sensor (bank 1) (view with en-
gine removed)

2.

Knock sensor (bank 2) (view with en-
gine removed)

3.

Battery current sensor

4.

Power steering pressure sensor

5.

Intake manifold

6.

Engine coolant temperature sensor

2010 Pathfinder

ENGINE CONTROL SYSTEM

EC-519

< FUNCTION DIAGNOSIS >

[VK56DE]

C

D

E

F

G

H

I

J

K

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M

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EC

N

P

O

7.

Ignition coil (with power transistor) 
(bank2)

8.

Ignition coil (with power transistor) 
(bank 1)

9.

Fuel injector harness connectors 
(bank 2)

10. Fuel injector harness connectors 

(bank 1)
: Vehicle front

PBIB2710E

1.

A/F sensor 1 (bank 2)

2.

A/F sensor 1(bank 1)

3.

Heated oxygen sensor 2
(bank 1)

4.

Heated oxygen sensor 2
(bank 2)
: Vehicle front

AWBIA0083ZZ

2010 Pathfinder

EC-520

< FUNCTION DIAGNOSIS >

[VK56DE]

ENGINE CONTROL SYSTEM

1.

ASCD steering switch

2.

MAIN switch

3.

CANCEL switch

4.

SET/COAST switch

5.

RESUME/ACCELERATE switch

6.

ECM harness connectors (view with 
ECM cover removed)

7.

Coolant reservoir

8.

Accelerator pedal position sensor

9.

Fuel level sensor unit and fuel pump 
harness connector (view with fuel 
tank removed)

AWBIA0084ZZ

2010 Pathfinder

ENGINE CONTROL SYSTEM

EC-521

< FUNCTION DIAGNOSIS >

[VK56DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

10. Fuel pump, fuel level sensor unit and 

fuel filter

11. Fuel pressure regulator

12. ASCD brake switch

13. Stop lamp switch

14. Brake pedal

2010 Pathfinder

EC-522

< FUNCTION DIAGNOSIS >

[VK56DE]

MULTIPORT FUEL INJECTION SYSTEM

MULTIPORT FUEL INJECTION SYSTEM

System Description

INFOID:0000000005257499

INPUT/OUTPUT SIGNAL CHART

*1: This sensor is not used to control the engine system. This is used only for the on board diagnosis.
*2: This signal is sent to the ECM via the CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.

SYSTEM DESCRIPTION

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 and intake air) from the crankshaft position sensor, the camshaft position

sensor and the mass air flow 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.

<Fuel increase>

• During warm-up

• When starting the engine

• During acceleration

• Hot-engine operation

• When selector lever position is changed from N to D

• High-load, high-speed operation

<Fuel decrease>

• During deceleration

• During high engine speed operation

Sensor

Input signal to ECM

ECM function

Actuator

Crankshaft position sensor (POS)

Engine speed*

3

Piston position

Fuel injection 
& mixture ratio 
control

Fuel injector

Camshaft position sensor (PHASE)

Mass air flow sensor

Amount of intake air

Engine coolant temperature sensor

Engine coolant temperature

Air fuel ratio (A/F) sensor 1

Density of oxygen in exhaust gas

Throttle position sensor

Throttle position

Accelerator pedal position sensor

Accelerator pedal position

Knock sensor

Engine knocking condition

Battery

Battery voltage*

3

Power steering pressure sensor

Power steering operation

Heated oxygen sensor 2*

1

Density of oxygen in exhaust gas

ABS actuator and electric unit (control unit)

VDC/TCS operation command*

2

Air conditioner switch

Air conditioner operation*

2

Unified meter control unit

Gear position

Vehicle speed*

2

2010 Pathfinder

MULTIPORT FUEL INJECTION SYSTEM

EC-523

< FUNCTION DIAGNOSIS >

[VK56DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

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 then better reduce CO, HC and NOx emissions. This system uses air

fuel ratio (A/F) sensor 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-630, "Component Description"

. This maintains the mixture ratio within the range of sto-

ichiometric (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

• 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., 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.

“Long-term fuel trim” is overall fuel compensation carried out overtime to compensate for continual deviation of

the “short-term fuel trim” from the central value. Continual deviation will occur due to individual engine differ-

ences, wear over time and changes in the usage environment.

PBIB3020E

2010 Pathfinder

 

 

 

 

 

 

 

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