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Nissan Pathfinder (2008 year). Manual - part 353

NORMAL OPERATING CONDITION

EC-941

< SYMPTOM DIAGNOSIS >

[VK56DE]

NORMAL OPERATING CONDITION

Fuel Cut Control (at No Load and High Engine Speed)

INFOID:0000000001538022

INPUT/OUTPUT SIGNAL CHART

*: This signal is sent to the ECM through CAN communication line.

SYSTEM DESCRIPTION

If the engine speed is above 1,800 rpm under no load (for example, the shift position is neutral and engine
speed over is 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 be operated until the engine speed reaches 1,500 rpm, then fuel cut will be cancelled.
NOTE:
This function is different from deceleration control listed under

EC-508, "System Description"

Sensor

Input signal to ECM

ECM function

Actuator

Park/neutral position (PNP) switch

Neutral position

Fuel cut control

Fuel injector

Accelerator pedal position sensor

Accelerator pedal position

Engine coolant temperature sensor

Engine coolant temperature

Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)

Engine speed

Wheel sensor

Vehicle speed*

EC-942

< PRECAUTION >

[VK56DE]

PRECAUTIONS

PRECAUTION

PRECAUTIONS

Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"

INFOID:0000000001538023

The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.

WARNING:

• To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death in

the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.

• Improper maintenance, including incorrect removal and installation of the SRS, can lead to personal

injury caused by unintentional activation of the system. For removal of Spiral Cable and Air Bag
Module, see the SRS section.

• Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this

Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or har-
ness connectors.

On Board Diagnosis (OBD) System of Engine and A/T

INFOID:0000000001538024

The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.

CAUTION:

• Be sure to turn the ignition switch OFF and disconnect the negative battery cable before any repair

or inspection work. The open/short circuit of related switches, sensors, solenoid valves, etc. will
cause the MIL to light up.

• Be sure to connect and lock the connectors securely after work. A loose (unlocked) connector will

cause the MIL to light up due to the open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)

• Certain systems and components, especially those related to OBD, may use a new style slide-lock-

ing type harness connector. For description and how to disconnect, refer to

PG-62

• Be sure to route and secure the harnesses properly after work. The interference of the harness with

a bracket, etc. may cause the MIL to light up due to the short circuit.

• Be sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube

may cause the MIL to light up due to the malfunction of the EVAP system or fuel injection system,
etc.

• Be sure to erase the unnecessary malfunction information (repairs completed) from the ECM and

TCM (Transmission control module) before returning the vehicle to the customer.

Precaution

INFOID:0000000001538025

• Always use a 12 volt battery as power source.
• Do not attempt to disconnect battery cables while engine is

running.

• Before connecting or disconnecting the ECM harness con-

nector, turn ignition switch OFF and disconnect negative bat-
tery cable. Failure to do so may damage the ECM because
battery voltage is applied to ECM even if ignition switch is
turned OFF.

• Before removing parts, turn ignition switch OFF and then dis-

connect negative battery cable.

SEF289H

PRECAUTIONS

EC-943

< PRECAUTION >

[VK56DE]

• Do not disassemble ECM.
• If a battery cable is disconnected, the memory will return to

the ECM value.
The ECM will now start to self-control at its initial value.
Engine operation can vary slightly when the terminal is dis-
connected. However, this is not an indication of a malfunc-
tion. Do not replace parts because of a slight variation.

• If the battery is disconnected, the following emission-related

diagnostic information will be lost within 24 hours.

- Diagnostic trouble codes
- 1st trip diagnostic trouble codes
- Freeze frame data
- 1st trip freeze frame data
- System readiness test (SRT) codes
- Test values
• When connecting ECM harness connector, fasten it securely

with a lever as far as it will go as shown in the figure.

• When connecting or disconnecting pin connectors into or

from ECM, take care not to damage pin terminals (bend or
break).
Make sure that there are not any bends or breaks on ECM pin
terminal, when connecting pin connectors.

• Securely connect ECM harness connectors.

A poor connection can cause an extremely high (surge) volt-
age to develop in coil and condenser, thus resulting in dam-
age to ICs.

• Keep engine control system harness at least 10 cm (4 in) away

from adjacent harness, to prevent engine control system mal-
functions due to receiving external noise, degraded operation
of ICs, etc.

• Keep engine control system parts and harness dry.
• Before replacing ECM, perform ECM Terminals and Reference

Value inspection and make sure ECM functions properly.
Refer to

EC-888, "ECM Terminal and Reference Value"

• Handle mass air flow sensor carefully to avoid damage.
• Do not disassemble mass air flow sensor.
• Do not clean mass air flow sensor with any type of detergent.
• Do not disassemble electric throttle control actuator.
• Even a slight leak in the air intake system can cause serious

incidents.

• Do not shock or jar the camshaft position sensor (PHASE),

crankshaft position sensor (POS).

PBIB1164E

PBIB1512E

PBIB0090E

MEF040D

EC-944

< PRECAUTION >

[VK56DE]

PRECAUTIONS

• After performing each TROUBLE DIAGNOSIS, perform DTC

Confirmation Procedure or Overall Function Check.
The DTC should not be displayed in the DTC Confirmation
Procedure if the repair is completed. The Overall Function
Check should be a good result if the repair is completed.

• When measuring ECM signals with a circuit tester, never allow

the two tester probes to contact.
Accidental contact of probes will cause a short circuit and
damage the ECM power transistor.

• Do not use ECM ground terminals when measuring input/out-

put voltage. Doing so may result in damage to the ECM's tran-
sistor. Use a ground other than ECM terminals, such as the
ground.

• B1 indicates the bank 1, B2 indicates the bank 2 as shown in

the figure.

SEF217U

SEF348N

PBIB1144E

PRECAUTIONS

EC-945

< PRECAUTION >

[VK56DE]

• Do not operate fuel pump when there is no fuel in lines.
• Tighten fuel hose clamps to the specified torque.

• Do not depress accelerator pedal when starting.
• Immediately after starting, do not rev up engine unnecessar-

ily.

• Do not rev up engine just prior to shutdown.

• When installing C.B. ham radio or a mobile phone, be sure to

observe the following as it may adversely affect electronic
control systems depending on installation location.

- Keep the antenna as far as possible from the electronic con-

trol units.

- Keep the antenna feeder line more than 20 cm (8 in) away

from the harness of electronic controls.
Do not let them run parallel for a long distance.

- Adjust the antenna and feeder line so that the standing-wave

radio can be kept smaller.

- Be sure to ground the radio to vehicle body.

BBIA0529E

SEF709Y

SEF708Y

EC-946

< PREPARATION >

[VK56DE]

PREPARATION

PREPARATION

Special Service Tool

INFOID:0000000001538026

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

EG17650301
(J-33984-A)
Radiator cap tester
adapter

Adapting radiator cap tester to radiator cap and ra-
diator filler neck
a: 28 (1.10) dia.
b: 31.4 (1.236) dia.
c: 41.3 (1.626) dia.
Unit: mm (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-45488)
Quick connector re-
lease

Remove fuel tube quick connectors in engine
room.

(J-23688)
Engine coolant refrac-
tometer

Checking concentration of ethylene glycol in en-
gine coolant

S-NT564

LEC642

LBIA0376E

PBIC0198E

WBIA0539E

PREPARATION

EC-947

< PREPARATION >

[VK56DE]

Commercial Service Tool

INFOID:0000000001538027

Tool name
(Kent-Moore No.)

Description

Leak detector
i.e.: (J-41416)

Locating the 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

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

EC-948

< ON-VEHICLE MAINTENANCE >

[VK56DE]

FUEL PRESSURE

ON-VEHICLE MAINTENANCE

FUEL PRESSURE

Fuel Pressure Check

INFOID:0000000001538028

FUEL PRESSURE RELEASE

With CONSULT-III

Turn ignition switch ON.

Perform “FUEL PRESSURE RELEASE” in “WORK SUPPORT” mode with CONSULT-III.

Start engine.

After engine stalls, crank it two or three times to release all fuel pressure.

Turn ignition switch OFF.

Without CONSULT-III

Remove fuel pump fuse (1) located in IPDM E/R (2).

Start engine.

After engine stalls, crank it two or three times to release all fuel
pressure.

Turn ignition switch OFF.

Reinstall fuel pump fuse after servicing fuel system.

FUEL PRESSURE CHECK

CAUTION:

• Before disconnecting fuel line, release fuel pressure from fuel line to eliminate danger.
• Be careful not to scratch or get the fuel hose connection area dirty when servicing, so that the quick

connector o-ring maintains sealability.

• Use Fuel Pressure Gauge Kit J-44321 and Fuel Pressure Adapter J-44321-6 to check fuel pressure.
• Do not perform fuel pressure check with electrical system operating (i.e. lights, rear defog, A/C, etc.).

Fuel pressure gauge may indicate false readings due to varying engine loads and changes in mani-
fold vacuum.

NOTE:
Prepare pans or saucers under the disconnected fuel line because the fuel may spill out. The fuel pres-
sure cannot be completely released because R51 models do not have fuel return system.

Release fuel pressure to zero. Refer to "FUEL PRESSURE RELEASE".

Remove engine cover.

Remove fuel hose using Quick Connector Release J-45488. Refer to

EM-166, "Removal and Installation"

• Do not twist or kink fuel hose because it is plastic hose.
• Do not remove fuel hose from quick connector.
• Keep fuel hose connections clean.

Install Fuel Pressure Adapter J-44321-6 and Fuel Pressure
Gauge (from kit J-44321) (1) as shown in figure.
• Do not distort or bend fuel rail tube when installing fuel pres-

sure gauge adapter.

• When reconnecting fuel hose, check the original fuel hose for

damage and abnormality.

Turn ignition switch ON (reactivate fuel pump), and check for
fuel leakage.

Start engine and check for fuel leakage.

Read the indication of fuel pressure gauge.
• During fuel pressure check, check for fuel leakage from fuel

connection every 3 minutes.

ALBIA0351ZZ

ALBIA0367ZZ

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