2001 INFINITI QX4 IDX

SFE419AA
SFE420A
FUEL TANKNBFE0004S011. Release fuel pressure from fuel line.
Refer to MA-16, ªChanging Fuel Filterº.
2. Remove inspection hole cover located behind the rear seat.
3. Disconnect harness connectors under inspection hole cover.
4. Disconnect fuel hoses.
IPut mating marks on hoses for correct installation.
SFE468A
5. Disconnect filler hose, vent hose and evaporation hose at fuel
tank side.
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FUEL SYSTEM
Removal and Installation (Cont'd)
FE-5

SFE544A
5. Disconnect the quick connectors as follows.
1) Put mating marks on tubes and connectors for correct instal-
lation.
2) Hold the sides of the connector, push in tabs, and pull out the
tube inserted in the retainer.
CAUTION:
IThe tube can be removed when the push in tabs are com-
pletely depressed. Do not twist it more than necessary.
IDo not use any tools to remove the quick connector.
IKeep the connecting portion of the tubes and quick con-
nectors clean.
SFE425A
6. Remove fuel pump with bracket while lifting the pawl of the fuel
pump bracket upward.
AFE113
7. To install, reverse the removal procedure. Connect the quick
connectors as follows.
IBe sure that the connecting portion is clean and smooth.
IAlign mating marks.
IInsert tube into the center of the connector until you hear a
click.
AFE114
After connecting quick connectors, make sure the connection is
firmly made using the following method.
IPull on the fuel tube and connector to make sure they are firmly
connected.
IStart the engine, increase engine speed and verify that there
are no leaks.
SFE428A
IInstall fuel gauge as shown.
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FUEL SYSTEM
Removal and Installation (Cont'd)
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SFE636A
1. Heated oxygen sensor 2 (rear)
(bank 1)
2. Front tube
3. Heated oxygen sensor 2 (rear)
(bank 2)4. Dynamic damper (If so equipped)
5. Mounting rubber
6. Clamp
7. Mounting bracket8. Mounting rubber
9. Main muffler
10. Post muffler
11. TWC (under floor)
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EXHAUST SYSTEM
Removal and Installation (Cont'd)
FE-9

GENERAL INFORMATION
SECTION
GI
CONTENTS
PRECAUTIONS...............................................................3
Precautions ..................................................................3
PRECAUTIONS FOR SUPPLEMENTAL
RESTRAINT SYSTEM (SRS)²AIR BAG²AND
²SEAT BELT PRE-TENSIONER²
.................................3
PRECAUTIONS FOR IVIS (INFINITI VEHICLE
IMMOBILIZER SYSTEM - NATS)
.................................3
PRECAUTIONS FOR INFINITI COMMUNICATOR
(IVCS)
.......................................................................4
GENERAL PRECAUTIONS.........................................5
PRECAUTIONS FOR MULTIPORT FUEL
INJECTION SYSTEM OR ENGINE CONTROL
SYSTEM
...................................................................6
PRECAUTIONS FOR THREE WAY CATALYST...........6
PRECAUTIONS FOR HOSES.....................................7
PRECAUTIONS FOR ENGINE OILS...........................8
PRECAUTIONS FOR FUEL........................................8
PRECAUTIONS FOR AIR CONDITIONING..................8
HOW TO USE THIS MANUAL........................................9
HOW TO READ WIRING DIAGRAMS.......................... 11
Sample/Wiring Diagram - EXAMPL - ........................ 11
OPTIONAL SPLICE..................................................12
Description .................................................................13
CONNECTOR SYMBOLS.........................................15
HARNESS INDICATION...........................................16
COMPONENT INDICATION......................................16
SWITCH POSITIONS...............................................16
DETECTABLE LINES AND NON-DETECTABLE
LINES
.....................................................................17
MULTIPLE SWITCH.................................................18
REFERENCE AREA.................................................19
HOW TO CHECK TERMINAL.......................................21
Connector and Terminal Pin Kit.................................21
How to Probe Connectors .........................................21
PROBING FROM HARNESS SIDE............................21
PROBING FROM TERMINAL SIDE...........................21
How to Check Enlarged Contact Spring of
Terminal .....................................................................22
Waterproof Connector Inspection ..............................23
RUBBER SEAL INSPECTION...................................23
WIRE SEAL INSPECTION........................................23Terminal Lock Inspection ...........................................23
HOW TO PERFORM EFFICIENT DIAGNOSIS
FOR AN ELECTRICAL INCIDENT...............................24
Work Flow ..................................................................24
Incident Simulation Tests ...........................................25
INTRODUCTION......................................................25
VEHICLE VIBRATION..............................................25
HEAT SENSITIVE....................................................26
FREEZING..............................................................26
WATER INTRUSION................................................27
ELECTRICAL LOAD.................................................27
COLD OR HOT START UP.......................................27
Circuit Inspection .......................................................27
INTRODUCTION......................................................27
TESTING FOR²OPENS²IN THE CIRCUIT................28
TESTING FOR²SHORTS²IN THE CIRCUIT..............29
GROUND INSPECTION...........................................30
VOLTAGE DROP TESTS..........................................30
CONTROL UNIT CIRCUIT TEST...............................32
HOW TO FOLLOW TROUBLE DIAGNOSIS................34
How to Follow Test Groups in Trouble Diagnosis .....35
Key to Symbols Signifying Measurements or
Procedures.................................................................36
CONSULT-II CHECKING SYSTEM...............................38
Function and System Application ..............................38
Nickel Metal Hydride Battery Replacement...............39
Checking Equipment..................................................39
CONSULT-II Data Link Connector (DLC) Circuit ......40
INSPECTION PROCEDURE.....................................40
IDENTIFICATION INFORMATION................................41
Model Variation ..........................................................41
PREFIX AND SUFFIX DESIGNATIONS.....................41
Identification Number .................................................41
VEHICLE IDENTIFICATION NUMBER
ARRANGEMENT
.....................................................42
IDENTIFICATION PLATE..........................................42
ENGINE SERIAL NUMBER.......................................43
AUTOMATIC TRANSMISSION NUMBER...................43
TRANSFER SERIAL NUMBER..................................43
Dimensions ................................................................43
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PrecautionsNBGI0001Observe the following precautions to ensure safe and proper
servicing. These precautions are not described in each indi-
vidual section.
SGI646
PRECAUTIONS FOR SUPPLEMENTAL RESTRAINT
SYSTEM (SRS) ªAIR BAGº AND ªSEAT BELT
PRE-TENSIONERº
NBGI0001S01The Supplemental Restraint System such as ªAIR BAGº and ªSEAT
BELT PRE-TENSIONERº used along with a seat belt, helps to
reduce the risk or severity of injury to the driver and front passen-
ger for certain types of collision. The SRS system composition
which is available to INFINITI QX4 is as follows:
IFor a frontal collision
The Supplemental Restraint System consists of driver air bag
module (located in the center of the steering wheel), front pas-
senger air bag module (located on the instrument panel on
passenger side), seat belt pre-tensioners, a diagnosis sensor
unit, warning lamp, wiring harness and spiral cable.
IFor a side collision
The Supplemental Restraint System consists of side air bag
module (located in the outer side of front seat), satellite sensor,
diagnosis sensor unit (one of components of air bags for a
frontal collision), wiring harness, warning lamp (one of compo-
nents of air bags for a frontal collision).
Information necessary to service the system safely is included in
theRS sectionof this Service Manual.
WARNING:
ITo 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 INFINITI
dealer.
IImproper 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 RS section.
IDo not use electrical test equipment on any circuit related
to the SRS unless instructed to in this Service Manual.
Spiral cable and wiring harnesses covered with yellow
insulation tape either just before the harness connectors
or for the complete harness are related to the SRS.
PRECAUTIONS FOR IVIS (INFINITI VEHICLE
IMMOBILIZER SYSTEM Ð NATS)
NBGI0001S08IVIS (NATS) will immobilize the engine if someone tries to start it
without the registered key of IVIS (NATS).
Both of the originally supplied ignition key IDs have been IVIS
(NATS) registered.
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PRECAUTIONS
Precautions
GI-3

SGI285
GENERAL PRECAUTIONSNBGI0001S02IDo not operate the engine for an extended period of time
without proper exhaust ventilation.
Keep the work area well ventilated and free of any inflammable
materials. Special care should be taken when handling any
inflammable or poisonous materials, such as gasoline, refrig-
erant gas, etc. When working in a pit or other enclosed area,
be sure to properly ventilate the area before working with haz-
ardous materials.
Do not smoke while working on the vehicle.
SGI231
IBefore jacking up the vehicle, apply wheel chocks or other tire
blocks to the wheels to prevent the vehicle from moving. After
jacking up the vehicle, support the vehicle weight with safety
stands at the points designated for proper lifting before work-
ing on the vehicle.
These operations should be done on a level surface.
IWhen removing a heavy component such as the engine or
transaxle/transmission, be careful not to lose your balance and
drop it. Also, do not allow it to strike adjacent parts, especially
the brake tubes and master cylinder.
SEF289H
IBefore starting repairs which do not require battery power:
Turn off ignition switch.
Disconnect the negative battery terminal.
SGI233
ITo prevent serious burns:
Avoid contact with hot metal parts.
Do not remove the radiator cap when the engine is hot.
SGI234
IBefore servicing the vehicle:
Protect fenders, upholstery and carpeting with appropriate cov-
ers.
Take caution that keys, buckles or buttons do not scratch paint.
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PRECAUTIONS
Precautions (Cont'd)
GI-5

Do not place the vehicle on flammable material. Keep flammable
material off the exhaust pipe and the three way catalyst.
SMA019D
PRECAUTIONS FOR HOSESNBGI0001S10Hose Removal and InstallationNBGI0001S1001ITo prevent damage to rubber hose, do not pry off rubber hose
with tapered tool or screwdriver.
SMA020D
ITo reinstall the rubber hose securely, make sure of hose inser-
tion length and clamp orientation. (If tube is equipped with
hose stopper, insert rubber hose into tube until it butts up
against hose stopper.)
SMA021D
Hose ClampingNBGI0001S1002IIf old rubber hose is re-used, install hose clamp in its original
position (at the indentation where the old clamp was). If there
is a trace of tube bulging left on the old rubber hose, align
rubber hose at that position.
IDiscard old clamps; replace with new ones.
SMA022D
IAfter installing leaf spring clamps, apply force to them in the
direction of the arrow, tightening rubber hose equally all
around.
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PRECAUTIONS
Precautions (Cont'd)
GI-7

NBGI0002
IThe captionsWARNINGandCAUTIONwarn you of steps that must be followed to prevent personal injury
and/or damage to some part of the vehicle.
WARNINGindicates the possibility of personal injury if instructions are not followed.
CAUTIONindicates the possibility of component damage if instructions are not followed.
BOLD TYPED STATEMENTSexceptWARNINGandCAUTIONgive you helpful information.
IALPHABETICAL INDEXis provided at the end of this manual so that you can rapidly find the item and
page you are searching for.
IA QUICK REFERENCE INDEX, a black tab (e.g.
) is provided on the first page. You can quickly find
the first page of each section by mating it to the section's black tab.
ITHE CONTENTSare listed on the first page of each section.
ITHE TITLEis indicated on the upper portion of each page and shows the part or system.
ITHE PAGE NUMBERof each section consists of two letters which designate the particular section and a
number (e.g. ªBR-5º).
ITHE LARGE ILLUSTRATIONSare exploded views (See below.) and contain tightening torques, lubrica-
tion points, section number of thePARTS CATALOG(e.g. SEC. 440) and other information necessary to
perform repairs.
The illustrations should be used in reference to service matters only. When ordering parts, refer to the
appropriatePARTS CATALOG.
SBR364AC
ITHE SMALL ILLUSTRATIONSshow the important steps such as inspection, use of special tools, knacks
of work and hidden or tricky steps which are not shown in the previous large illustrations.
Assembly, inspection and adjustment procedures for the complicated units such as the automatic transaxle
or transmission, etc. are presented in a step-by-step format where necessary.
ITheUNITSgiven in this manual are primarily expressed as the SI UNIT (International System of Unit),
and alternatively expressed in the metric system and in the yard/pound system.
ªExampleº
Tightening torque:
59 - 78 N´m (6.0 - 8.0 kg-m, 43 - 58 ft-lb)
ITROUBLE DIAGNOSESare included in sections dealing with complicated components.
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HOW TO USE THIS MANUAL
GI-9