2001 INFINITI QX4 air condition

NBEL0145
Use the chart below to find out what each wiring
diagram code stands for.
Refer to the wiring diagram code in the alphabetical
index to find the location (page number) of each
wiring diagram.
Code Section Wiring Diagram Name
1STSIG AT A/T 1ST Signal
2NDSIG AT A/T 2ND Signal
3RDSIG AT A/T 3RD Signal
4THSIG AT A/T 4TH Signal
A/C, A HA Auto Air Conditioner
AAC/V EC IACV-AAC Valve
ABS BR Anti-lock Brake System
AP/SEN EC Absolute Pressure Sensor
ASCD EL Automatic Speed Control Device
AT/C EC A/T Control
ATDIAG EC A/T Diagnosis Communication
Line
AT/IND EL A/T Indicator Lamp
AUDIO EL Audio
AUT/DP EL Automatic Drive Positioner
BA/FTS AT A/T Fluid Temperature Sensor
and TCM Power Supply
BACK/L EL Back-up Lamp
BYPS/V EC Vacuum Cut Valve Bypass Valve
CHARGE SC Charging System
CHIME EL Warning Chime
CIGAR EL Cigarette Lighter
CLOCK EL Clock
COMPAS EL Compass and Thermometer
D/LOCK EL Power Door Lock
DEF EL Rear Window Defogger
DTRL EL Headlamp Ð With Daytime Light
System Ð
ECTS EC Engine Coolant Temperature Sen-
sor
ENGSS AT Engine Speed Signal
F/FOG EL Front Fog Lamp
F/LID EL Fuel Lid Opener
F/PUMP EC Fuel Pump Control
FICD EC IACV-FICD Solenoid Valve
FLS1 EC Fuel Gauge
Code Section Wiring Diagram Name
FLS2 EC Fuel Gauge
FLS3 EC Fuel Gauge
FTS AT A/T Fluid Temperature Sensor
FUELLH EC Fuel Injection System Function
(Left Bank)
FUELRH EC Fuel Injection System Function
(Right Bank)
H/AIM EL Headlamp Aiming Control System
H/LAMP EL Headlamp
HORN EL Horn
HSEAT EL Heated Seat
IATS EC Intake Air Temperature Sensor
IGN/SG EC Ignition Signal
ILL EL Illumination
INJECT EC Injector
INT/L EL Interior, Spot, Vanity Mirror, and
Luggage Room Lamps
IVC-L EC Intake Valve Timing Control Sole-
noid Valve LH
IVC-R EC Intake Valve Timing Control Sole-
noid Valve RH
IVCS EL INFINITI Communicator
IVCS-L EC Intake Valve Timing Control Posi-
tion Sensor LH
IVCS-R EC Intake Valve Timing Control Posi-
tion Sensor RH
KS EC Knock Sensor
LAN AT A/T Communication Line
LOAD EC Electrical Load Signal
LPSV AT Line Pressure Solenoid Valve
MAFS EC Mass Air Flow Sensor
MAIN AT Main Power Supply and Ground
Circuit
MAIN EC Main Power Supply and Ground
Circuit
METER EL Speedometer, Tachometer, Temp.,
Oil, and Fuel Gauges
MIL/DL EC MIL and Data Link Connectors
MIRROR EL Door Mirror
MULTI EL Multi-remote Control System
NATS EL IVIS (Infiniti Vehicle Immobiliser
System)
GI
MA
EM
LC
EC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
IDX
WIRING DIAGRAM CODES (CELL CODES)
EL-457

NVH Troubleshooting Ð Engine NoiseNBEM0005S01Use the chart below to help you find the cause of the symptom.
1. Locate the area where noise occurs.
2. Confirm the type of noise.
3. Specify the operating condition of engine.
4. Check specified noise source.
If necessary, repair or replace these parts.
Location of
noiseType of
noiseOperating condition of engine
Source of
noiseCheck itemReference
page Before
warm-upAfter
warm-upWhen
startingWhen
idlingWhen
racingWhile
driving
To p o f
engine
Rocker
cover
Cylinder
headTicking or
clickingC A ÐA BÐTappet
noiseValve clearance EM-54
Rattle C A Ð A B CCamshaft
bearing
noiseCamshaft journal clear-
ance
Camshaft runoutEM-42, 42
Crankshaft
pulley
Cylinder
block
(Side of
engine)
Oil panSlap or
knockÐ A ÐB BÐPiston pin
noisePiston and piston pin
clearance
Connecting rod bush-
ing clearanceEM-63, 70
Slap or
rapA ÐÐBBAPiston slap
noisePiston-to-bore clear-
ance
Piston ring side clear-
ance
Piston ring end gap
Connecting rod bend
and torsionEM-64, 64,
65, 66
Knock A B C B B BConnect-
ing rod
bearing
noiseConnecting rod bush-
ing clearance (Small
end)
Connecting rod bearing
clearance (Big end)EM-70, 69
Knock A B Ð A B CMain bear-
ing noiseMain bearing oil clear-
ance
Crankshaft runoutEM-67, 67
Front of
engine
Timing
chain
coverTapping or
tickingA A ÐBBBTiming
chain and
chain ten-
sioner
noiseTiming chain cracks
and wear
Timing chain tensioner
operationEM-29, 20
Front of
engineSqueaking
or fizzingA B ÐBÐCOther
drive belts
(Sticking
or slipping)Drive belts deflectionMA section
(ªChecking
Drive
Beltsº,
ªENGINE
MAINTE-
NANCEº) Creaking A BABABOther
drive belts
(Slipping)Idler pulley bearing
operation
Squall
CreakA B ÐBABWater
pump
noiseWater pump operationLC section
(ªWater
Pump
Inspectionº,
ªENGINE
COOLING
SYSTEMº)
A: Closely related B: Related C: Sometimes related Ð: Not related
GI
MA
LC
EC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
NOISE, VIBRATION AND HARSHNESS (NVH) TROUBLESHOOTING
NVH Troubleshooting Ð Engine Noise
EM-9

SEM934C
VALVE SEATSNBEM0019S10Check valve seats for any evidence of pitting at valve contact
surface, and reseat or replace if it has worn out excessively.
IBefore repairing valve seats, check valve and valve guide
for wear. If they have worn, replace them. Then correct
valve seat.
IUse both hands to cut uniformly.
SEM795A
REPLACING VALVE SEAT FOR SERVICE PARTSNBEM0019S111. Bore out old seat until it collapses. Boring should not continue
beyond the bottom face of the seat recess in cylinder head. Set
the machine depth stop to ensure this.
2. Ream cylinder head recess for service valve seat.
Oversize [0.5 mm (0.020 in)]:
Intake 38.500 - 38.516 mm (1.5157 - 1.5164 in)
Exhaust 32.700 - 32.716 mm (1.2874 - 1.2880 in)
Be sure to ream in circles concentric to the valve guide
center.
This will enable valve seat to fit correctly.
SEM892B
3. Heat cylinder head to 110 to 130ÉC (230 to 266ÉF) by soaking
in heated oil.
4. Press fit valve seat until it seats on the bottom.
5. Cut or grind valve seat using suitable tool to the specified
dimensions as shown in SDS (EM-79).
6. After cutting, lap valve seat with abrasive compound.
7. Check valve seating condition.
Seat face angle ªaº: 45É
Contacting width ªWº:
Intake 1.09 - 1.31 mm (0.0429 - 0.0516 in)
Exhaust 1.29 - 1.51 mm (0.0508 - 0.0594 in)
SEM621F
8. Use a depth gauge to measure the distance between the
mounting surface of the cylinder head spring seat and the
valve stem end. If the distance is shorter than specified, repeat
step 5 above to adjust it. If it is longer, replace the valve seat
with a new one.
Valve seat resurface limit ªLº:
Intake 41.07 - 41.67 mm (1.6169 - 1.6405 in)
Exhaust 41.00 - 41.60 mm (1.6142 - 1.6378 in)
GI
MA
LC
EC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
CYLINDER HEAD
Inspection (Cont'd)
EM-45

Rear Engine MountingNBEM0042S0102
SEM459G
SEM605G
SEM461G
SEM324F
1. Release fuel pressure.
Refer to EC-39, ªFuel pressure releaseº.
2. Remove engine hood and front RH and LH wheels.
3. Remove engine undercover and suspension member stay.
4. Drain coolant from radiator.
5. Remove the following parts.
IRadiator shroud
IRadiator
ICooling fan
IDrive belts
IBattery
IEngine cover
IThrottle wires
6. Air duct with air cleaner case.
7. Disconnect vacuum hoses, fuel hoses, heater hoses, EVAP
canister hoses, harnesses, connectors and so on.
8. Remove air conditioner compressor from bracket, then put it
aside holding with a suitable wire.
9. Remove power steering oil pump and reservoir tank with
bracket, then put it aside holding with a suitable wire.
10. Remove alternator.
11. Remove exhaust front tube heat insulators, then remove rear
heated oxygen sensors.
12. Remove exhaust front and rear tubes.
Refer to FE-8, ªRemoval and Installationº.
13. Remove transmission with transfer.
Refer to AT-277, ªRemovalº.
14. Remove TWC (manifold) heat insulators, then remove TWC
(manifold).
15. Install engine slingers.
16. Hoist engine with engine slingers and remove front engine
mounting nuts.
GI
MA
LC
EC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
ENGINE ASSEMBLY
Removal and Installation (Cont'd)
EM-59

QUICK REFERENCE CHART: QX42001
Engine model VQ35DE
Firing order 1-2-3-4-5-6
Idle speed rpmA/T
(in ªNº position)750 50
Ignition timing (degree BTDC at idle speed) 15É 2É
CO% at idleIdle mixture screw is preset and
sealed at factory.
Drive belt deflection (Cold) mm (in) Used belt
Deflection of
new belt
LimitDeflection
after
adjustment
Alternator
Power steering oil pump
Fan7 (0.28)4-5
(0.16 - 0.20)3.5 - 4.5
(0.138 - 0.177)
Air conditioner compressor 12 (0.472)9-10
(0.354 - 0.394)8-9
(0.31 - 0.35)
Applied pressed force
N (kg, lb)98 (10, 22)
Drive belt tension adjustment (Cold)
N (kg, lb)Used belt
New belt
LimitAfter
adjustment
Alternator
Power steering pump
Fan294 (30, 66)730 - 818
(74.4 - 83.5,
164 - 184)838 - 926
(85.4 - 94.5,
188 - 208)
Air conditioner compressor 196 (20, 44)348 - 436
(35.5 - 44.5,
78 - 98)470 - 559
(47.9 - 57.0,
106 - 126)
Radiator cap relief pressure
kPa (kg/cm
2, psi)78 - 98 (0.8 - 1.0, 11 - 14)
Cooling system leakage testing pressure
kPa (kg/cm
2, psi)157 (1.6, 23)
Compression pressure
kPa (kg/cm
2, psi)/rpmStandard 1,275 (13.0, 185)/300
Minimum 981 (10.0, 142)/300
Spark plugStandard PLFR5A-11
Cold PLFR6A-11
Hot PLFR4A-11
Applied model 245/70 R16 tire
Camber
Degree minute
(Decimal degree)Minimum þ0É35¢(þ0.58É)
Nominal 0É10¢(0.17É)
Maximum 0É55¢(0.92É)
Left and right
difference45¢(0.75É) or less
Caster
Degree minute
(Decimal degree)Minimum 2É15¢(2.25É)
Nominal 3É00¢(3.00É)
Maximum 3É45¢(3.75É)
Left and right
difference45¢(0.75É) or less
Total toe-in Minimum 1 (0.04)
Distance (A þ B)
mm (in)Nominal 2 (0.08)
Maximum 3 (0.12)
Angle (left plus right)
Degree minute
(Decimal degree)Minimum 5¢(0.08É)
Nominal 10¢(0.17É)
Maximum 15¢(0.25É)
Wheel turning angle
(Full turn)Minimum 30É00¢(30.00É)
Inside
Degree minute
(Decimal degree)Nominal 33É00¢(33.00É)
Maximum 34É00¢(34.00É)
Outside
Degree minute
(Decimal degree)Minimum 28É00¢(28.00É)
Nominal 31É00¢(31.00É)
Maximum 32É00¢(32.00É)
* Fuel, radiator coolant and engine oil full.
Spare tire, jack, hand tools and mats in designated positions.
Unit: mm (in)Front brake
Pad wear limit 2.0 (0.079)
Rotor repair limit 26.0 (1.024)
Rear brake
Lining wear limit 1.5 (0.059)
Drum repair limit 296.5 (11.67)
Pedal free height 175 - 185 (6.89 - 7.28)
Pedal depressed height*1 70 (2.76)
Parking brake
Number of notches*2 6 - 8
*1 Under force of 490 N (50 kg, 110 lb) with engine running
*2 At pulling force: 196 N (20 kg, 44 lb)
Unit Liter US measure
Coolant with reservoir 9.2 9-3/4 qt
Engine*With oil filter 5.0 5-1/4 qt
Without oil filter 4.8 5-1/8 qt
Dry engine (engine overhaul) 6.8 7-1/4 qt
Transmis-
sionA/T2WD
8.5 9 qt
4WD
All-mode 4WD transfer 3.0 2-5/8 qt
Differential carrierFront 1.85 3-7/8 pt
Rear 2.8 5-7/8 pt
Power steering system 0.9 1 qt
Air conditioning systemRefrigerant 0.60 - 0.70 kg 1.32 - 1.54 lb
Compressor
oil0.20 6.8 fl oz
* For further details, see ªChanging Engine Oilº in MA section.
Preload
(At hub bolt)
N (kg, lb)Wheel bearing lock nut
78-98(8-10,58-72)
Tightening torque
N×m (kg-m, ft-lb)
Retightening torque after loosen-
ing wheel bearing lock nut
N×m (kg-m, in-lb)0.5 - 1.5 (0.05 - 0.15, 4.3 - 13.0)
Axial end play
mm (in)0 (0)
Starting force at wheel hub bolt
N (kg, lb)A
Turning angle
degree15É - 30É
Starting force at wheel hub bolt
N (kg, lb)B
Wheel bearing preload at wheel hub
bolt
B þ A N (kg, lb)7.06 - 20.99 (0.72 - 2.14, 1.59 - 4.72)

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
MA
EM
LC
EC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX

PRECAUTIONS FOR ENGINE OILSNBGI0001S05Prolonged and repeated contact with used engine oil may cause
skin cancer. Try to avoid direct skin contact with used oil.
If skin contact is made, wash thoroughly with soap or hand cleaner
as soon as possible.
Health Protection PrecautionsNBGI0001S0501IAvoid prolonged and repeated contact with oils, particularly
used engine oils.
IWear protective clothing, including impervious gloves where
practicable.
IDo not put oily rags in pockets.
IAvoid contaminating clothes, particularly underpants, with oil.
IHeavily soiled clothing and oil-impregnated footwear should
not be worn. Overalls must be cleaned regularly.
IFirst Aid treatment should be obtained immediately for open
cuts and wounds.
IUse barrier creams, applying them before each work period, to
help the removal of oil from the skin.
IWash with soap and water to ensure all oil is removed (skin
cleansers and nail brushes will help). Preparations containing
lanolin replace the natural skin oils which have been removed.
IDo not use gasoline, kerosine, diesel fuel, gas oil, thinners or
solvents for cleaning skin.
IIf skin disorders develop, obtain medical advice without delay.
IWhere practicable, degrease components prior to handling.
IWhere there is a risk of eye contact, eye protection should be
worn, for example, chemical goggles or face shields; in addi-
tion an eye wash facility should be provided.
Environmental Protection PrecautionsNBGI0001S0502Burning used engine oil in small space heaters or boilers can be
recommended only for units of approved design. The heating sys-
tem must meet the requirements of HM Inspectorate of Pollution for
small burners of less than 0.4 MW. If in doubt check with the
appropriate local authority and/or manufacturer of the approved
appliance.
Dispose of used oil and used oil filters through authorized waste
disposal contractors to licensed waste disposal sites, or to the
waste oil reclamation trade. If in doubt, contact the local authority
for advice on disposal facilities.
It is illegal to pour used oil on to the ground, down sewers or drains,
or into water courses.
The regulations concerning pollution vary between regions.
PRECAUTIONS FOR FUELNBGI0001S06Use unleaded gasoline with an octane rating of at least 87 AKI
(Anti-Knock Index) number (research octane number 91).
CAUTION:
Do not use leaded gasoline. Using leaded gasoline will dam-
age the three way catalyst.
Using a fuel other than that specified could adversely affect
the emission control devices and systems, and could also
affect the warranty coverage validity.
PRECAUTIONS FOR AIR CONDITIONINGNBGI0001S07Use an approved refrigerant recovery unit any time the air condi-
tioning system must be discharged. Refer to HA-144, ªHFC-134a
(R-134a) Service Procedureº for specific instructions.
PRECAUTIONS
Precautions (Cont'd)
GI-8

ISERVICE DATA AND SPECIFICATIONSare contained at the end of each section for quick reference of
data.
IThe followingSYMBOLS AND ABBREVIATIONSare used:
SYMBOL ABBREVIATION SYMBOL ABBREVIATION
Tightening torque
2WD2-Wheel Drive
Should be lubricated with grease. Unless oth-
erwise indicated, use recommended multi-pur-
pose grease.A/CAir Conditioner
Should be lubricated with oil. P/S Power Steering
Sealing point SST Special Service Tools
Checking point SAE Society of Automotive Engineers, Inc.
Always replace after every disassembly. ATF Automatic Transmission Fluid
qP
Apply petroleum jelly.
D1Drive range 1st gear
Apply ATF. D2Drive range 2nd gear
HSelect with proper thickness. D
3Drive range 3rd gear
IAdjustment is required. D
4Drive range 4th gear
SDS Service Data and Specifications OD Overdrive
LH, RH Left-Hand, Right-Hand 2
22nd range 2nd gear
FR, RR Front, Rear 2
12nd range 1st gear
M/T Manual Transaxle/Transmission 1
21st range 2nd gear
A/T Automatic Transaxle/Transmission 1
11st range 1st gear
,
4WD4-Wheel Drive
HOW TO USE THIS MANUAL
GI-10