elec INFINITI QX4 2001 Factory Service Manual

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

IClean all disassembled parts in the designated liquid or solvent
prior to inspection or assembly.
IReplace oil seals, gaskets, packings, O-rings, locking washers,
cotter pins, self-locking nuts, etc. with new ones.
IReplace inner and outer races of tapered roller bearings and
needle bearings as a set.
IArrange the disassembled parts in accordance with their
assembled locations and sequence.
IDo not touch the terminals of electrical components which use
microcomputers (such as ECMs).
Static electricity may damage internal electronic components.
IAfter disconnecting vacuum or air hoses, attach a tag to indi-
cate the proper connection.
IUse only the fluids and lubricants specified in this manual.
IUse approved bonding agent, sealants or their equivalents
when required.
IUse tools and recommended special tools where specified for
safe and efficient service repairs.
IWhen repairing the fuel, oil, water, vacuum or exhaust
systems, check all affected lines for leaks.
IDispose of drained oil or the solvent used for cleaning parts in
an appropriate manner.
WARNING:
To prevent ECM from storing the diagnostic trouble codes, do
not carelessly disconnect the harness connectors which are
related to the engine control system and TCM (Transmission
Control Module) system. The connectors should be discon-
nected only when working according to the WORK FLOW of
TROUBLE DIAGNOSES in EC and AT sections.
SGI787
PRECAUTIONS FOR MULTIPORT FUEL INJECTION
SYSTEM OR ENGINE CONTROL SYSTEM
NBGI0001S03IBefore connecting or disconnecting any harness connector for
the multiport fuel injection system or ECM (Engine Control
Module):
Turn ignition switch to OFF position.
Disconnect negative battery terminal.
Otherwise, there may be damage to ECM.
IBefore disconnecting pressurized fuel line from fuel pump to
injectors, be sure to release fuel pressure.
IBe careful not to jar components such as ECM and mass air
flow sensor.
PRECAUTIONS FOR THREE WAY CATALYSTNBGI0001S04If a large amount of unburned fuel flows into the catalyst, the cata-
lyst temperature will be excessively high. To prevent this, follow the
instructions below:
IUse unleaded gasoline only. Leaded gasoline will seriously
damage the three way catalyst.
IWhen checking for ignition spark or measuring engine
compression, make tests quickly and only when necessary.
IDo not run engine when the fuel tank level is low, otherwise the
engine may misfire causing damage to the catalyst.
PRECAUTIONS
Precautions (Cont'd)
GI-6

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

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

Number Item Description
20 System branchIThis shows that the system branches to another system identified by cell code (section
and system).
21 Page crossingIThis arrow shows that the circuit continues to another page identified by cell code.
IThe C will match with the C on another page within the system other than the next or pre-
ceding pages.
22 Shielded lineIThe line enclosed by broken line circle shows shield wire.
23Component box in
wave lineIThis shows that another part of the component is also shown on another page (indicated
by wave line) within the system.
24 Component nameIThis shows the name of a component.
25 Connector numberIThis shows the connector number.
IThe letter shows which harness the connector is located in.
IExample:M: main harness. For detail and to locate the connector, refer to EL-442, ªMain
Harnessº. A coordinate grid is included for complex harnesses to aid in locating connec-
tors.
26 Ground (GND)IThe line spliced and grounded under wire color shows that ground line is spliced at the
grounded connector.
27 Ground (GND)IThis shows the ground connection.
28 Connector viewsIThis area shows the connector faces of the components in the wiring diagram on the
page.
29 Common componentIConnectors enclosed in broken line show that these connectors belong to the same com-
ponent.
30 Connector colorIThis shows a code for the color of the connector. For code meaning, refer to wire color
codes, Number 14 of this chart.
31Fusible link and fuse
boxIThis shows the arrangement of fusible link(s) and fuse(s), used for connector views of
ªPOWER SUPPLY ROUTINGº in EL section.
The open square shows current flow in, and the shaded square shows current flow out.
32 Reference areaIThis shows that more information on the Super Multiple Junction (SMJ), Electrical Units
etc., exists at the end of the manual. Refer to GI-19 for details.
HOW TO READ WIRING DIAGRAMS
Description (Cont'd)
GI-14

REFERENCE AREA=NBGI0003S0208The Reference Area of the wiring diagram contains references to
additional electrical reference pages at the end of the manual. If
connector numbers and titles are shown in the Reference Area of
the wiring diagram, these connector symbols are not shown in the
Connector Area.
SGI092A
Super multiple junction (SMJ)
In a wiring diagram, the SMJ connectors include a letter of the
alphabet in the terminal number.
SMJ connector numbers are shown in the Reference Area of the
wiring diagram. SMJ terminal arrangement can be found on the
electrical reference pages at the end of the manual. For terminal
arrangement of these connectors, refer to the ªSUPER MULTIPLE
JUNCTION (SMJ)º electrical reference page at the end of the
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HOW TO READ WIRING DIAGRAMS
Description (Cont'd)
GI-19

manual.
Fuse block Ð Junction box (J/B)
Fuse block Ð Junction box (J/B) connector number is shown in the
Reference Area of the wiring diagram. For connector terminal and
fuse arrangement, refer to the ªFUSE BLOCK Ð Junction Box
(J/B)º electrical reference page at the end of the manual.
Fuse and fusible link box
For fuse arrangement in the fuse and fusible link box, refer to the
ªFUSE AND FUSIBLE LINK BOXº electrical reference page at the
end of the manual.
Electrical units
Electrical unit connector symbols are shown in the Connector Area
of the wiring diagram.
However, when there is not enough space to show the connector
terminal arrangement in the Connector Area of the wiring diagram,
the electrical unit connector number is shown in the Reference
Area of the wiring diagram. For electrical unit connector terminal
arrangement, refer to the ªELECTRICAL UNITSº electrical refer-
ence page at the end of the manual. Most of the electrical unit
connectors on this page are shown from the harness side of the
connector.
Joint connector
Joint connector symbols are shown in the connector area of the
wiring diagram. For connector internal wiring layout and joint con-
nector terminal arrangement, refer to the ªJOINT CONNECTOR
(J/C)º electrical reference page at the end of the manual.
HOW TO READ WIRING DIAGRAMS
Description (Cont'd)
GI-20

NBGI0004
Work FlowNBGI0004S01
SGI838
STEP DESCRIPTION
STEP 1 Get detailed information about the conditions and the environment when the incident occurred.
The following are key pieces of information required to make a good analysis:
WHATVehicle Model, Engine, Transmission and the System (i.e. Radio).
WHENDate, Time of Day, Weather Conditions, Frequency.
WHERERoad Conditions, Altitude and Traffic Situation.
HOWSystem Symptoms, Operating Conditions (Other Components Interaction).
Service History and if any After Market Accessories have been installed.
STEP 2 Operate the system, road test if necessary.
Verify the parameter of the incident.
If the problem can not be duplicated, refer to ªIncident Simulation Testsº next page.
STEP 3 Get the proper diagnosis materials together including:
POWER SUPPLY ROUTING
System Operation Descriptions
Applicable Service Manual Sections
Check for any Service Bulletin.
Identify where to begin diagnosis based upon your knowledge of the system operation and the cus-
tomer comments.
STEP 4 Inspect the system for mechanical binding, loose connectors or wiring damage.
Determine which circuits and components are involved and diagnose using the Power Supply Routing
and Harness Layouts.
STEP 5 Repair or replace the incident circuit or component.
STEP 6 Operate the system in all modes. Verify the system works properly under all conditions. Make sure you
have not inadvertently created a new incident during your diagnosis or repair steps.
HOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN ELECTRICAL INCIDENT
Work Flow
GI-24

Incident Simulation TestsNBGI0004S02INTRODUCTIONNBGI0004S0201Sometimes the symptom is not present when the vehicle is brought
in for service. If possible, re-create the conditions present at the
time of the incident. Doing so may help avoid a No Trouble Found
Diagnosis. The following section illustrates ways to simulate the
conditions/environment under which the owner experiences an
electrical incident.
The section is broken into the six following topics:
IVehicle vibration
IHeat sensitive
IFreezing
IWater intrusion
IElectrical load
ICold or hot start up
Get a thorough description of the incident from the customer. It is
important for simulating the conditions of the problem.
VEHICLE VIBRATIONNBGI0004S0202The problem may occur or become worse while driving on a rough
road or when engine is vibrating (idle with A/C on). In such a case,
you will want to check for a vibration related condition. Refer to the
illustration below.
Connectors & Harness
Determine which connectors and wiring harness would affect the
electrical system you are inspecting.Gentlyshake each connec-
tor and harness while monitoring the system for the incident you
are trying to duplicate. This test may indicate a loose or poor elec-
trical connection.
Hint
Connectors can be exposed to moisture. It is possible to get a thin
film of corrosion on the connector terminals. A visual inspection
may not reveal this without disconnecting the connector. If the
problem occurs intermittently, perhaps the problem is caused by
corrosion. It is a good idea to disconnect, inspect and clean the
terminals on related connectors in the system.
Sensors & Relays
Gentlyapply a slight vibration to sensors and relays in the system
you are inspecting.
This test may indicate a loose or poorly mounted sensor or relay.
SGI839
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HOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN ELECTRICAL INCIDENT
Incident Simulation Tests
GI-25

Engine Compartment
There are several reasons a vehicle or engine vibration could
cause an electrical complaint. Some of the things to check for are:
IConnectors not fully seated.
IWiring harness not long enough and is being stressed due to
engine vibrations or rocking.
IWires laying across brackets or moving components.
ILoose, dirty or corroded ground wires.
IWires routed too close to hot components.
To inspect components under the hood, start by verifying the integ-
rity of ground connections. (Refer to GROUND INSPECTION
described later.) First check that the system is properly grounded.
Then check for loose connection bygently shakingthe wiring or
components as previously explained. Using the wiring diagrams
inspect the wiring for continuity.
Behind The Instrument Panel
An improperly routed or improperly clamped harness can become
pinched during accessory installation. Vehicle vibration can aggra-
vate a harness which is routed along a bracket or near a screw.
Under Seating Areas
An unclamped or loose harness can cause wiring to be pinched by
seat components (such as slide guides) during vehicle vibration. If
the wiring runs under seating areas, inspect wire routing for pos-
sible damage or pinching.
SGI842
HEAT SENSITIVENBGI0004S0203The owner's problem may occur during hot weather or after car has
sat for a short time. In such cases you will want to check for a heat
sensitive condition.
To determine if an electrical component is heat sensitive, heat the
component with a heat gun or equivalent.
Do not heat components above 60ÉC (140ÉF).If incident occurs
while heating the unit, either replace or properly insulate the com-
ponent.
SGI843
FREEZINGNBGI0004S0204The customer may indicate the incident goes away after the car
warms up (winter time). The cause could be related to water freez-
ing somewhere in the wiring/electrical system.
There are two methods to check for this. The first is to arrange for
the owner to leave his car overnight. Make sure it will get cold
enough to demonstrate his complaint. Leave the car parked out-
side overnight. In the morning, do a quick and thorough diagnosis
of those electrical components which could be affected.
HOW TO PERFORM EFFICIENT DIAGNOSIS FOR AN ELECTRICAL INCIDENT
Incident Simulation Tests (Cont'd)
GI-26