Infiniti I30. Emission Control System (2003 year). Manual

Multiport Fuel Injection (MFI) System

DESCRIPTION

NHEC0014

Input/Output Signal Chart

NHEC0014S01

Sensor

Input Signal to ECM

ECM func-

tion

Actuator

Crankshaft position sensor (POS)

Engine speed
Piston position

Fuel injec-
tion & mix-
ture ratio
control

Injectors

Camshaft position sensor (PHASE)

Mass air flow sensor

Amount of intake air

Engine coolant temperature sensor

Engine coolant temperature

Heated oxygen 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

Vehicle speed (From combination meter)

Vehicle speed

Ignition switch

Start signal

Air conditioner switch

Air conditioner operation

Knock sensor

Engine knocking condition

Battery

Battery voltage

Absolute pressure sensor

Ambient air barometric pressure

Power steering pressure sensor

Power steering operation

Heated oxygen sensor 2*

Density of oxygen in exhaust gas

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

Basic Multiport Fuel Injection System

NHEC0014S02

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

NHEC0014S03

In addition, the amount of fuel injected is compensated to improve engine performance under various oper-
ating conditions as listed below.
<Fuel increase>

쐌

During warm-up

쐌

When starting the engine

쐌

During acceleration

쐌

Hot-engine operation

쐌

When selector lever is changed from “N” to “D”

쐌

High-load, high-speed operation

<Fuel decrease>

쐌

During deceleration

쐌

During high engine speed operation

IDX

ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION

Multiport Fuel Injection (MFI) System

EC-33

Mixture Ratio Feedback Control (Closed loop control)

NHEC0014S04

SEF336WC

The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission con-
trol. The three way catalyst (Manifold) can then better reduce CO, HC and NOx emissions. This system uses
a heated oxygen 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
the heated oxygen sensor 1, refer to EC-241. This maintains the mixture ratio within the range of stoichiomet-
ric (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 the heated oxygen sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the sig-
nal from the heated oxygen sensor 2.

Open Loop Control

NHEC0014S05

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.

쐌

Deceleration and acceleration

쐌

High-load, high-speed operation

쐌

Malfunction of heated oxygen sensor 1 or its circuit

쐌

Insufficient activation of heated oxygen sensor 1 at low engine coolant temperature

쐌

High engine coolant temperature

쐌

During warm-up

쐌

After shifting from “N” to “D”

쐌

When starting the engine

Mixture Ratio Self-learning Control

NHEC0014S06

The mixture ratio feedback control system monitors the mixture ratio signal transmitted from the heated oxy-
gen sensor 1. This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close
to the theoretical 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 during 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 the heated oxygen sensor 1 indicates whether the mixture ratio is RICH or LEAN com-
pared to the theoretical 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 long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.

ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION

Multiport Fuel Injection (MFI) System (Cont’d)

EC-34

Fuel Injection Timing

NHEC0014S07

SEF179U

Two types of systems are used.
Sequential Multiport Fuel Injection System

NHEC0014S0701

Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System

NHEC0014S0702

Fuel is injected simultaneously into all six cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The six injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.

Fuel Shut-off

NHEC0014S08

Fuel to each cylinder is cut off during deceleration or operation of the engine at excessively high speeds.

Electronic Ignition (EI) System

DESCRIPTION

NHEC0015

Input/Output Signal Chart

NHEC0015S01

Sensor

Input Signal to ECM

ECM func-

tion

Actuator

Crankshaft position sensor (POS)

Engine speed

Ignition tim-
ing control

Power transistor

Camshaft position sensor (PHASE)

Piston position

Mass air flow sensor

Amount of intake air

Engine coolant temperature sensor

Engine coolant temperature

Throttle position sensor

Throttle position

Accelerator pedal position sensor

Accelerator pedal position

Vehicle speed (From combination meter)

Vehicle speed

Ignition switch

Start signal

Knock sensor

Engine knocking

Park/neutral position (PNP) switch

Gear position

Battery

Battery voltage

IDX

ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION

Multiport Fuel Injection (MFI) System (Cont’d)

EC-35

System Description

NHEC0015S02

SEF742M

The ignition timing is controlled by the ECM to maintain the best air-fuel ratio for every running condition of
the engine. The ignition timing data is stored in the ECM. This data forms the map shown.
The ECM receives information such as the injection pulse width and camshaft position sensor signal. Com-
puting this information, ignition signals are transmitted to the power transistor.
e.g.,

N: 1,800 rpm, Tp: 1.50 msec

A °BTDC

During the following conditions, the ignition timing is revised by the ECM according to the other data stored
in the ECM.

쐌

At starting

쐌

During warm-up

쐌

At idle

쐌

At low battery voltage

쐌

During acceleration

The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.

Air Conditioning Cut Control

DESCRIPTION

NHEC0016

Input/Output Signal Chart

NHEC0016S01

Sensor

Input Signal to ECM

ECM function

Actuator

Air conditioner switch

Air conditioner “ON” signal

Air conditioner cut
control

Air conditioner relay

Throttle position sensor

Throttle valve opening angle

Crankshaft position sensor (POS)

Engine speed

Engine coolant temperature sensor

Engine coolant temperature

Ignition switch

Start signal

Vehicle speed (From combination meter)

Vehicle speed

Refrigerant pressure sensor

Refrigerant pressure

Power steering pressure sensor

Power steering operation

System Description

NHEC0016S02

This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned off.

쐌

When the accelerator pedal is fully depressed.

쐌

When cranking the engine.

쐌

At high engine speeds.

쐌

When the engine coolant temperature becomes excessively high.

쐌

When operating power steering during low engine speed or low vehicle speed.

ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION

Electronic Ignition (EI) System (Cont’d)

EC-36

쐌

When engine speed is excessively low.

쐌

When refrigerant pressure is excessively low or high.

Fuel Cut Control (at no load & high engine
speed)

DESCRIPTION

NHEC0017

Input/Output Signal Chart

NHEC0017S01

Sensor

Input Signal to ECM

ECM func-

tion

Actuator

Vehicle speed (From combination meter)

Vehicle speed

Fuel cut
control

Injectors

Park/neutral position (PNP) switch

Neutral position

Engine coolant temperature sensor

Engine coolant temperature

Crankshaft position sensor (POS)

Engine speed

If the engine speed is above 1,800 rpm with no load (for example, the shift position is neutral and engine speed
is over 1,800 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies based on
engine speed.
Fuel cut will operate until the engine speed reaches 1,500 rpm, then fuel cut is cancelled.
NOTE:
This function is different from deceleration control listed under “Multiport Fuel Injection (MFI) System”, EC-33.

Evaporative Emission System

DESCRIPTION

NHEC0018

SEF569XC

The evaporative emission system is used to reduce hydrocarbons emitted into the atmosphere from the fuel
system. This reduction of hydrocarbons is accomplished by activated charcoals in the EVAP canister.
The fuel vapor in the sealed fuel tank is led into the EVAP canister which contains activated carbon and the
vapor is stored there when the engine is not operating or when refueling to the fuel tank.
The vapor in the EVAP canister is purged by the air through the purge line to the intake manifold when the
engine is operating. EVAP canister purge volume control solenoid valve is controlled by ECM. When the engine
operates, the flow rate of vapor controlled by EVAP canister purge volume control solenoid valve is propor-
tionally regulated as the air flow increases.
EVAP canister purge volume control solenoid valve also shuts off the vapor purge line during decelerating and
idling.

IDX

ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION

Air Conditioning Cut Control (Cont’d)

EC-37

SEF396T

INSPECTION

NHEC0019

EVAP Canister

NHEC0019S01

Check EVAP canister as follows:
1.

Pinch the fresh air hose.

Blow air into port A and check that it flows freely out of port B.

SEF397T

Tightening Torque

NHEC0019S02

Tighten EVAP canister as shown in the figure.
Make sure new O-ring is installed properly between EVAP can-
ister and EVAP canister vent control valve.

SEF445Y

SEF943S

Fuel Tank Vacuum Relief Valve (Built into fuel filler cap)

NHEC0019S03

Wipe clean valve housing.

Check valve opening pressure and vacuum.

Pressure:

15.3 - 20.0 kPa (0.156 - 0.204 kg/cm

, 2.22 - 2.90 psi)

Vacuum:

−6.0 to −3.3 kPa (−0.061 to −0.034 kg/cm

, −0.87 to

−0.48 psi)

If out of specification, replace fuel filler cap as an assembly.

CAUTION:

Use only a genuine fuel filler cap as a replacement. If an incor-
rect fuel filler cap is used, the MIL may come on.

Vacuum Cut Valve and Vacuum Cut Valve Bypass Valve

NHEC0019S04

Refer to EC-593.

EVAP Canister Purge Volume Control Solenoid Valve

NHEC0019S05

Refer to EC-356.

Fuel Tank Temperature Sensor

NHEC0019S06

Refer to EC-285.

ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION

Evaporative Emission System (Cont’d)

EC-38

SEF462UA

EVAP Service Port

NHEC0019S07

Positive pressure is delivered to the EVAP system through the
EVAP service port. If fuel vapor leakage in the EVAP system
occurs, use a leak detector to locate the leak.

SEF200U

PEF838U

PEF917U

How to Detect Fuel Vapor Leakage

NHEC0019S08

CAUTION:

쐌

Never use compressed air or a high pressure pump.

쐌

Do not exceed 4.12 kPa (0.042 kg/cm

, 0.6 psi) of pressure

in EVAP system.

NOTE:

쐌

Do not start engine.

쐌

Improper installation of EVAP service port adapter to the EVAP
service port may cause a leak.

With CONSULT-II

NHEC0019S0801

Attach the EVAP service port adapter securely to the EVAP
service port.

Also attach the pressure pump and hose to the EVAP service
port adapter.

Turn ignition switch “ON”.

Select the “EVAP SYSTEM CLOSE” of “WORK SUPPORT
MODE” with CONSULT-II.

Touch “START”. A bar graph (Pressure indicating display) will
appear on the screen.

Apply positive pressure to the EVAP system until the pressure
indicator reaches the middle of the bar graph.

Remove EVAP service port adapter and hose with pressure
pump.

Locate the leak using a leak detector. Refer to “EVAPORATIVE
EMISSION LINE DRAWING”, EC-41.

IDX

ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION

Evaporative Emission System (Cont’d)

EC-39

SEF462UA

SEF254X

Without CONSULT-II

NHEC0019S0802

Attach the EVAP service port adapter securely to the EVAP
service port.

Also attach the pressure pump with pressure gauge to the
EVAP service port adapter.

Apply battery voltage to between the terminals of both EVAP
canister vent control valve and vacuum cut valve bypass valve
to make a closed EVAP system.

To locate the leak, deliver positive pressure to the EVAP sys-
tem until pressure gauge points reach 1.38 to 2.76 kPa (0.014
to 0.028 kg/cm

, 0.2 to 0.4 psi).

Remove EVAP service port adapter and hose with pressure
pump.

Locate the leak using a leak detector. Refer to “EVAPORATIVE
EMISSION LINE DRAWING”, EC-41.

ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION

Evaporative Emission System (Cont’d)

EC-40

EVAPORATIVE EMISSION LINE DRAWING

NHEC1421

SEC896CA

IDX

ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION

Evaporative Emission System (Cont’d)

EC-41

On Board Refueling Vapor Recovery (ORVR)

NHEC0744

SYSTEM DESCRIPTION

NHEC0744S01

SEF206VA

SEF830X

From the beginning of refueling, the fuel tank pressure goes up. When the pressure reaches the setting value
of the refueling control valve (RCV) opening pressure, the RCV is opened. After RCV opens, the air and vapor
inside the fuel tank go through refueling EVAP vapor cut valve, RCV and refueling vapor line to the EVAP
canister. The vapor is absorbed by the EVAP canister and the air is released to the atmosphere.
When the refueling has reached the full level of the fuel tank, the refueling EVAP vapor cut valve is closed
and refueling is stopped because of auto shut-off. The vapor which was absorbed by the EVAP canister is
purged during driving.
The RCV is always closed during driving and the evaporative emission control system is operated the same
as conventional system.

WARNING:

When conducting inspections below, be sure to observe the following:

쐌

Put a “CAUTION: INFLAMMABLE” sign in workshop.

쐌

Do not smoke while servicing fuel system. Keep open flames and sparks away from work area.

쐌

Be sure to furnish the workshop with a CO

fire extinguisher.

IDX

ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION

On Board Refueling Vapor Recovery (ORVR)

EC-43

CAUTION:

쐌

Before removing fuel line parts, carry out the following procedures:

a) Put drained fuel in an explosion-proof container and put lid on securely.
b) Release fuel pressure from fuel line. Refer to “Fuel Pressure Release”, EC-56.
c) Disconnect battery ground cable.

쐌

Always replace O-ring when the fuel gauge retainer is removed.

쐌

Do not kink or twist hose and tube when they are installed.

쐌

Do not tighten hose and clamps excessively to avoid damaging hoses.

쐌

After installation, run engine and check for fuel leaks at connection.

쐌

Do not attempt to top off the fuel tank after the fuel pump nozzle shuts off automatically.
Continued refueling may cause fuel overflow, resulting in fuel spray and possibly a fire.

DIAGNOSTIC PROCEDURE

NHEC0744S02

Symptom: Fuel Odor from EVAP Canister Is Strong.

NHEC0744S0201

CHECK EVAP CANISTER

1. Remove EVAP canister with EVAP canister vent control valve attached.
2. Weigh the EVAP canister with EVAP canister vent control valve attached.

The weight should be less than 1.8 kg (4.0 lb).

OK or NG

䊳

GO TO 2.

䊳

GO TO 3.

CHECK IF EVAP CANISTER SATURATED WITH WATER

Does water drain from the EVAP canister?

SEF596U

Yes or No

Yes

䊳

GO TO 3.

No (With CONSULT-II)

䊳

GO TO 6.

No (Without CONSULT-
II)

䊳

GO TO 7.

REPLACE EVAP CANISTER

Replace EVAP canister with a new one.

䊳

GO TO 4.

ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION

On Board Refueling Vapor Recovery (ORVR) (Cont’d)

EC-44

CHECK WATER SEPARATOR

1. Check visually for insect nests in the water separator air inlet.
2. Check visually for cracks or flaws in the appearance.
3. Check visually for cracks or flaws in the hose.
4. Check that A and C are not clogged by blowing air into B with A, and then C plugged.

PBIB1032E

5. In case of NG in items 2 - 4, replace the parts.
NOTE:

쐌

Do not disassemble water separator.

OK or NG

䊳

GO TO 5.

䊳

Replace water separator.

DETECT MALFUNCTIONING PART

Check the EVAP hose between EVAP canister and water separator for clogging or poor connection.

䊳

Repair or replace EVAP hose.

IDX

ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION

On Board Refueling Vapor Recovery (ORVR) (Cont’d)

EC-45

CHECK REFUELING EVAP VAPOR CUT VALVE

With CONSULT-II

1. Remove fuel tank. Refer to FE-4, “FUEL SYSTEM”.
2. Drain fuel from the tank as follows:
a. Remove fuel feed hose located on the fuel gauge retainer.
b. Connect a spare fuel hose, one side to fuel gauge retainer where the hose was removed and the other side to a fuel

container.

c. Drain fuel using “FUEL PUMP RELAY” in “ACTIVE TEST” mode with CONSULT-II.
3. Check refueling EVAP vapor cut valve for being stuck to close as follows.

Blow air into the refueling EVAP vapor cut valve (from hose end B), and check that the air flows freely into the tank.

4. Check EVAP vapor cut valve for being stuck to open as follows.
a. Connect vacuum pump to hose ends A and B using a suitable 3-way connector.
b. Remove fuel gauge retainer with fuel gauge unit.

Always replace O-ring with new one.

c. Put fuel tank upside down.
d. Apply vacuum pressure to both hose ends A and B [−13.3 kPa (−100 mmHg, −3.94 inHg)] with fuel gauge retainer

remaining open and check that the pressure is applicable.

SEF968X

OK or NG

䊳

GO TO 8.

䊳

Replace refueling EVAP vapor cut valve with fuel tank.

ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION

On Board Refueling Vapor Recovery (ORVR) (Cont’d)

EC-46

CHECK REFUELING EVAP VAPOR CUT VALVE

Without CONSULT-II

1. Remove fuel tank. Refer to FE-4, “FUEL SYSTEM”.
2. Drain fuel from the tank as follows:
a. Remove fuel gauge retainer.
b. Drain fuel from the tank using a hand pump into a fuel container.
3. Check refueling EVAP vapor cut valve for being stuck to close as follows.

Blow air into the refueling EVAP vapor cut valve (from hose end B), and check that the air flows freely into the tank.

4. Check EVAP vapor cut valve for being stuck to open as follows.
a. Connect vacuum pump to hose ends A and B using a suitable 3-way connector.
b. Remove fuel gauge retainer with fuel gauge unit.

Always replace O-ring with new one.

c. Put fuel tank upside down.
d. Apply vacuum pressure to both hose ends A and B [−13.3 kPa (−100 mmHg, −3.94 inHg)] with fuel gauge retainer

remaining open and check that the pressure is applicable.

SEF968X

OK or NG

䊳

GO TO 8.

䊳

Replace refueling EVAP vapor cut valve with fuel tank.

CHECK REFUELING CONTROL VALVE

1. Remove fuel filler cap.
2. Check air continuity between hose ends A and B.

Blow air into the hose end B. Air should flow freely into the fuel tank.

3. Blow air into hose end A and check there is no leakage.
4. Apply pressure to both hose ends A and B [20 kPa (150 mmHg, 5.91 inHg)] using a pressure pump and a suitable

3-way connector. Check that there is no leakage.

SEF968X

OK or NG

䊳

INSPECTION END

䊳

Replace refueling control valve with fuel tank.

IDX

ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION

On Board Refueling Vapor Recovery (ORVR) (Cont’d)

EC-47

Symptom: Cannot Refuel/Fuel Odor From The Fuel Filler Opening Is Strong While
Refueling.

NHEC0744S0202

CHECK EVAP CANISTER

1. Remove EVAP canister with EVAP canister vent control valve attached.
2. Weigh the EVAP canister with EVAP canister vent control valve attached.

The weight should be less than 1.8 kg (4.0 lb).

OK or NG

䊳

GO TO 2.

䊳

GO TO 3.

CHECK IF EVAP CANISTER SATURATED WITH WATER

Does water drain from the EVAP canister?

SEF596U

Yes or No

Yes

䊳

GO TO 3.

䊳

GO TO 6.

REPLACE EVAP CANISTER

Replace EVAP canister with a new one.

䊳

GO TO 4.

ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION

On Board Refueling Vapor Recovery (ORVR) (Cont’d)

EC-48

Infiniti I30. Emission Control System (2003 year). Manual - part 3