Infiniti FX35 / FX45. Manual - part 317

PREPARATION

EC-29

< SERVICE INFORMATION >

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PREPARATION

Special Service Tool

INFOID:0000000001325893

The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.

Tool number
(Kent-Moore No.)
Tool name

Description

KV10117100
(J-36471-A)
Heated oxygen sensor 
wrench

Loosening or tightening heated oxygen sensor 
with 22 mm (0.87 in) hexagon nut

KV10114400
(J-38365)
Heated oxygen sensor 
wrench

Loosening or tightening air fuel ratio (A/F) sensor
a: 22 mm (0.87 in)

(J-44321)
Fuel pressure gauge 
kit

Checking fuel pressure

(J-44321-6)
Fuel pressure adapter

Connecting fuel pressure gauge to quick connec-
tor type fuel lines.

(J-44626)
Air fuel ratio (A/F)
sensor wrench

Loosening or tightening air fuel ratio (A/F) sensor 1

(J-45488)
Quick connector re-
lease

Remove fuel tube quick connectors in engine 
room.

S-NT379

S-NT636

LEC642

LBIA0376E

LEM054

PBIC0198E

EC-30

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PREPARATION

Commercial Service Tool

INFOID:0000000001325894

Tool name
(Kent-Moore No.)

Description

Leak detector 
i.e.: (J-41416)

Locating EVAP leak

EVAP service port 
adapter
i.e.: (J-41413-OBD)

Applying positive pressure through EVAP service 
port

Fuel filler cap adapter
i.e.: (MLR-8382)

Checking fuel tank vacuum relief valve opening 
pressure

Socket wrench

Removing and installing engine coolant tempera-
ture sensor

Oxygen sensor thread 
cleaner
i.e.: (J-43897-18)
(J-43897-12)

Reconditioning the exhaust system threads before 
installing a new oxygen sensor. Use with anti-
seize lubricant shown below.
a: 18 mm diameter with pitch 1.5 mm for Zirco-
nia Oxygen Sensor
b: 12 mm diameter with pitch 1.25 mm for Tita-
nia Oxygen Sensor

Anti-seize lubricant 

i.e.: (Permatex

TM

 

133AR or equivalent 
meeting MIL specifica-
tion MIL-A-907)

Lubricating oxygen sensor thread cleaning tool 
when reconditioning exhaust system threads.

S-NT703

S-NT704

S-NT815

S-NT705

AEM488

S-NT779

ENGINE CONTROL SYSTEM

EC-31

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ENGINE CONTROL SYSTEM

Schematic

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Multiport Fuel Injection (MFI) System

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INPUT/OUTPUT SIGNAL CHART

PBIB2281E

EC-32

< SERVICE INFORMATION >

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ENGINE CONTROL SYSTEM

*1: This sensor is not used to control the engine system under normal conditions.

*2: This signal is sent to the ECM through 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 both the crankshaft 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 is changed from N to D
• High-load, high-speed operation

<Fuel decrease>

• During deceleration
• During high engine speed operation

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 1 can then better reduce CO, HC and NOx emissions. This system uses air fuel ratio

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

Park/neutral position (PNP) switch

Gear 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

Air conditioner switch

Air conditioner operation*

2

Wheel sensor

Vehicle speed*

2

PBIB3020E