2001 INFINITI QX4 ESP

Removal and InstallationNBEM0042WARNING:
ISituate vehicle on a flat and solid surface.
IPlace chocks at front and back of rear wheels.
IDo not remove engine until exhaust system has com-
pletely cooled off. Otherwise, you may burn yourself
and/or fire may break out in fuel line.
IFor safety during subsequent steps, the tension of wires
should be slackened against the engine.
IBefore disconnecting fuel hose, release fuel pressure
from fuel line.
Refer to EC-39, ªFuel Pressure Releaseº.
IBefore removing front axle from transmission, place
safety stands under designated front supporting points.
Refer to GI section for lifting points and towing.
IBe sure to hoist engine and transmission in a safe man-
ner.
IFor engines not equipped with engine slingers, attach
proper slingers and bolts described in PARTS CATALOG.
CAUTION:
IWhen lifting engine, be careful not to strike adjacent parts,
especially accelerator wire casing, brake lines, and brake
master cylinder.
IIn hoisting the engine, always use engine slingers in a
safe manner.
IBefore separating engine and transmission, remove
crankshaft position sensor (POS) from the assembly.
IAlways take extra care not to damage edge of crankshaft
position sensor (POS), or ring gear teeth.GI
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ENGINE ASSEMBLY
Removal and Installation
EM-57

SEM845E
2. Install main bearing cap and bearing beam to cylinder block.
Tighten all bolts in correct order.
3. Measure inner diameters ªAº of each main bearing.
AEM033
4. Measure outer diameters ªDmº of each crankshaft main jour-
nal.
5. Calculate main bearing clearance.
Main bearing clearance = A þ Dm
Standard: 0.035 - 0.045 mm (0.0014 - 0.0018 in)
Limit: 0.065 mm (0.0026 in)
IIf it exceeds the limit, replace bearing.
IIf clearance cannot be adjusted using any standard bearing
grade, grind crankshaft journal and use undersized bearing.
SEM964
a. When grinding crankshaft journal, confirm that ªLº dimension in
fillet roll is more than the specified limit.
ªLº: 0.1 mm (0.004 in)
b. Refer to SDS for grinding crankshaft and available service
parts.
SEM451G
6. If crankshaft or cylinder block is replaced with a new one,
select thickness of main bearings as follows:
a. Grade number of each cylinder block main journal is punched
on the respective cylinder block. These numbers are punched
in either Arabic or Alphabet. Refer to SDS, EM-81.
If measured diameter is out of grade punched, decide suitable
grade using table in SDS.
SEM452G
b. Grade number of each crankshaft main journal is punched on
the respective crankshaft. These numbers are punched in
either Arabic or Alphabet. Refer to SDS, EM-84.
If measured diameter is out of grade punched, decide suitable
grade using table in SDS.
c. Select main bearing with suitable thickness according to the
following table.
Refer to ªSDSº, EM-85, for available main bearings.
CYLINDER BLOCK
Inspection (Cont'd)
EM-68

SEM452G
EM142
8. If crankshaft is replaced with a new one, select connecting rod
bearing according to the following table.
Connecting rod bearing grade number (Identification
color):
These numbers are punched in either Arabic or Roman numer-
als.
Crankshaft pin journal grade
numberConnecting rod bearing grade number
0 0 (Black)
1 1 (Brown)
2 2 (Green)
Method B (Using plastigage)
CAUTION:
IDo not turn crankshaft or connecting rod while plastigage
is being inserted.
IWhen bearing clearance exceeds the specified limit,
ensure that the proper bearing has been installed. If incor-
rect bearing clearance exists, use a thicker or undersized
main bearing to ensure specified clearance.
SEM673E
CONNECTING ROD BUSHING CLEARANCE (SMALL
END)
NBEM0027S091. Measure inner diameter ªCº of bushing.
2. Measure outer diameter ªDpº of piston pin.
3. Calculate connecting rod bushing clearance.
Connecting rod bushing clearance=CþDp
Standard: 0.005 - 0.017 mm (0.0002 - 0.0007 in)
Limit: 0.030 mm (0.0012 in)
If it exceeds the limit, replace connecting rod assembly or
connecting rod bushing and/or piston set with pin.
SEM849EB
SEM536G
DRIVE PLATE RUNOUTNBEM0027S11Runout (Total indicator reading):
Less than 0.15 mm (0.0059 in)
CAUTION:
IThe signal plate is built into the drive plate assembly. Be
careful not to damage the signal plate, especially the
teeth.
ICheck the drive plate and signal plate for deformation or
cracks.
IKeep any magnetized objects away from the signal plate.
IDo not allow any magnetic materials to contact the signal
plate teeth.
CYLINDER BLOCK
Inspection (Cont'd)
EM-70

SEM838F
AssemblyNBEM0028PISTONNBEM0028S011. Install new snap ring on one side of piston pin hole.
2. Heat piston to 60 to 70ÉC (140 to 158ÉF) and assemble piston,
piston pin, connecting rod and new snap ring.
IAlign the direction of piston and connecting rod.
INumbers stamped on connecting rod and cap correspond
to each cylinder.
IAfter assembly, make sure connecting rod swings
smoothly.
SEM453G
3. Set piston rings as shown.
CAUTION:
IWhen piston rings are not replaced, make sure that piston
rings are mounted in their original positions.
IWhen replacing piston rings, these without punchmarks,
present, piston rings can be mounted with either side up.
SEM160B
IAlign piston rings so that end gaps are positioned as
shown in the figure.
SEM454G
OIL JETNBEM0028S051. Install oil jets.
IInsert oil jet knock pin into the cylinder block knock pin hole,
and tighten the mounting bolts.
SEM175F
CRANKSHAFTNBEM0028S021. Set main bearings in their proper positions on cylinder block
and main bearing beam.
IConfirm that correct main bearings are used. Refer to
ªInspectionº of this section.
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CYLINDER BLOCK
Assembly
EM-71

SEM455G
5. Install connecting rod bearings in connecting rods and con-
necting rod caps.
IConfirm that correct bearings are used.
SEM620
6. Install pistons with connecting rods.
a. Install them into corresponding cylinders with Tool.
IBe careful not to scratch cylinder wall with the connecting
rod.
IArrange so that front mark on piston head faces toward
engine front.
SEM457G
b. Install connecting rod caps.
ILubricate threads and seat surfaces with new engine oil.
IInstall so that the cylinder number stamped on the connecting
rod agrees with that stamped on cap side.
IMake sure that front mark on the connecting rod cap faces the
front of the engine.
SEM538G
SEM953E
c. Re-use connecting rod cap bolts as follows.
IMake sure that the bolts can be smoothly screwed-in to the
end manually.
IIf not, measure the outer diameter ªdº shown in the figure.
Outer diameter ªdº of connecting rod cap bolt:
Standard
7.90 - 8.00 mm (0.3110 - 0.3150 in)
Limit
7.75 mm (0.3051 in)
d. Tighten connecting rod cap bolts to the specified torque.
Connecting rod cap bolt:
(1) Tighten nuts to 19 to 21 N´m (1.9 to 2.1 kg-m, 14
to 15 ft-lb).
(2) Turn nuts 90 to 95 degrees clockwise with angle
wrench.
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CYLINDER BLOCK
Assembly (Cont'd)
EM-73

The security indicator is located on the instrument panel. The indi-
cator blinks when the ignition switch is in OFF or ACC position.
Therefore, IVIS (NATS) warns outsiders that the vehicle is
equipped with the anti-theft system.
IWhen IVIS (NATS) detects trouble, the security indicator lamp
lights up while ignition switch is in ON position.
This lighting up indicates that the anti-theft is not functioning,
so prompt service is required.
IWhen servicing IVIS (NATS) (trouble diagnoses, system initial-
ization and additional registration of other IVIS (NATS) ignition
key IDs), CONSULT-II hardware and CONSULT-II IVIS (NATS)
software is necessary.
Regarding the procedures of IVIS (NATS) initialization and
IVIS (NATS) ignition key ID registration, refer to CONSULT-II
operation manual, IVIS/NVIS.
Therefore, CONSULT-II IVIS (NATS) software (program card
and operation manual) must be kept strictly confidential to
maintain the integrity of the anti-theft function.
IWhen servicing IVIS (NATS) (trouble diagnoses, system initial-
ization and additional registration of other IVIS (NATS) ignition
key IDs), it may be necessary to re-register original key iden-
tification. Therefore, be sure to receive all keys from vehicle
owner.
A maximum of five key IDs can be registered into IVIS (NATS).
IWhen failing to start the engine first time using the key of IVIS
(NATS) (for example, when interference is caused by another
IVIS (NATS) key, an automated full road device or automated
payment device on the key ring), restart as follows.
a) Leave the ignition switch in ON position for approximately 5
seconds.
b) Turn ignition switch to OFF or LOCK position and wait approxi-
mately 5 seconds.
c) Repeat step 1 and 2.
d) Restart the engine while holding the device (which may have
caused the interference) separate from the registered NATS
key. If the no start condition re-occurs, NISSAN recommends
placing the registered IVIS (NATS) key on a separate key ring
to avoid interference from other devices.
PRECAUTIONS FOR INFINITI COMMUNICATOR (IVCS)NBGI0001S09The purpose of INFINITI Communicator is to increase security for
the vehicle owner by providing a convenient way to contact the
most appropriate emergency assistance provider during an emer-
gency.
Improper operation of the system may result in a police response.
The theft warning system also activates INFINITI Communicator.
For details, refer to INFINITI Communicator (IVCS) in the EL sec-
tion.
PRECAUTIONS
Precautions (Cont'd)
GI-4

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

Description=NBGI0003S02
Number Item Description
1 Power conditionIThis shows the condition when the system receives battery positive voltage (can be oper-
ated).
2 Fusible linkIThe double line shows that this is a fusible link.
IThe open circle shows current flow in, and the shaded circle shows current flow out.
3Fusible link/fuse loca-
tionIThis shows the location of the fusible link or fuse in the fusible link or fuse box. For
arrangement, refer to EL-10, ªPOWER SUPPLY ROUTINGº.
4 FuseIThe single line shows that this is a fuse.
IThe open circle shows current flow in, and the shaded circle shows current flow out.
5 Current ratingIThis shows the current rating of the fusible link or fuse.
6 ConnectorsIThis shows that connector E3 is female and connector M1 is male.
IThe G/R wire is located in the 1A terminal of both connectors.
ITerminal number with an alphabet (1A, 5B, etc.) indicates that the connector is SMJ con-
nector. Refer to GI-19.
7 Optional spliceIThe open circle shows that the splice is optional depending on vehicle application.
8 SpliceIThe shaded circle shows that the splice is always on the vehicle.
9 Page crossingIThis arrow shows that the circuit continues to an adjacent page.
IThe A will match with the A on the preceding or next page.
10 Common connectorIThe dotted lines between terminals show that these terminals are part of the same con-
nector.
11 Option abbreviationIThis shows that the circuit is optional depending on vehicle application.
12 RelayIThis shows an internal representation of the relay. For details, refer to EL-7, ªSTANDARD-
IZED RELAYº.
13 ConnectorsIThis shows that the connector is connected to the body or a terminal with bolt or nut.
14 Wire colorIThis shows a code for the color of the wire.
B = Black
W = White
R = Red
G = Green
L = Blue
Y = Yellow
LG = Light GreenBR = Brown
OR = Orange
P = Pink
PU = Purple
GY = Gray
SB = Sky Blue
CH = Dark Brown
DG = Dark Green
When the wire color is striped, the base color is given first, followed by the stripe color as
shown below:
Example: L/W = Blue with White Stripe
15 Option descriptionIThis shows a description of the option abbreviation used on the page.
16 SwitchIThis shows that continuity exists between terminals 1 and 2 when the switch is in the A
position. Continuity exists between terminals 1 and 3 when the switch is in the B position.
17 Assembly partsIConnector terminal in component shows that it is a harness incorporated assembly.
18 Cell codeIThis identifies each page of the wiring diagram by section, system and wiring diagram
page number.
19 Current flow arrowIArrow indicates electric current flow, especially where the direction of standard flow (verti-
cally downward or horizontally from left to right) is difficult to follow.
IA double arrow ª
º shows that current can flow in either direction depending on cir-
cuit operation.
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HOW TO READ WIRING DIAGRAMS
Description
GI-13