Air INFINITI QX56 2004 Factory Service Manual

PRECAUTIONS
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Use approved bonding agent, sealants or their equivalents when required.

Use hand tools, power tools (disassembly only) and recom-
mended special tools where specified for safe and efficient ser-
vice repairs.

When repairing the fuel, oil, water, vacuum or exhaust systems,
check all affected lines for leaks.

Before servicing the vehicle:
Protect fenders, upholstery and carpeting with appropriate cov-
ers.
Take caution that keys, buckles or buttons do not scratch paint.
WA RN ING:
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 disconnected only when working according to the WORK FLOW of
TROUBLE DIAGNOSES in EC and AT sections.
Precautions for Three Way CatalystEAS00149
If a large amount of unburned fuel flows into the catalyst, the catalyst temperature will be excessively high. To
prevent this, follow the instructions.

Use unleaded gasoline only. Leaded gasoline will seriously damage the three way catalyst.

When checking for ignition spark or measuring engine compression, make tests quickly and only when
necessary.

Do not run engine when the fuel tank level is low, otherwise the engine may misfire, causing damage to
the catalyst.
Do not place the vehicle on flammable material. Keep flammable material off the exhaust pipe and the three
way catalyst.
Precautions for Fuel (Unleaded Premium Gasoline Required)EAS001KH
Use unleaded premium gasoline with an octane rating of at least 91 AKI (Anti-Knock Index) number (Research
octane number 96).
If unleaded premium gasoline is not available, unleaded regular gasoline with an octane rating of at least 87
AKI number (Research octane number 91) can be used, but only under the following precautions:

have the fuel tank filled only partially with unleaded regular gasoline, and fill up with unleaded premium
gasoline as soon as possible.

avoid full throttle driving and abrupt acceleration.
However, for maximum vehicle performance, the use of unleaded premium gasoline is recommended.
CAUTION:
Do not use leaded gasoline. Using leaded gasoline will damage the three way catalyst. Do not use E-85
fuel (85% fuel ethanol, 15% unleaded gasoline) unless the vehicle is specifically designed for E-85 fuel
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(i.e. Flexible Fuel Vehicle - FFV models). 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 Multiport Fuel Injection System or Engine Control SystemEAS0014B

Before connecting or disconnecting any harness connector for
the multiport fuel injection system or ECM:
Turn ignition switch to “OFF” position.
Disconnect negative battery terminal.
Otherwise, there may be damage to ECM.

Before disconnecting pressurized fuel line from fuel pump to
injectors, be sure to release fuel pressure.

Be careful not to jar components such as ECM and mass air
flow sensor.
Precautions for HosesEAS0014C
HOSE REMOVAL AND INSTALLATION

To prevent damage to rubber hose, do not pry off rubber hose
with tapered tool or screwdriver.

To 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.)
HOSE CLAMPING

If 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.

Discard old clamps; replace with new ones.
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After installing leaf spring clamps, apply force to them in the
direction of the arrow, tightening rubber hose equally all around.
Precautions for Engine OilsEAS0014D
Prolonged 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 PRECAUTIONS

Avoid prolonged and repeated contact with oils, particularly used engine oils.

Wear protective clothing, including impervious gloves where practicable.

Do not put oily rags in pockets.

Avoid contaminating clothes, particularly underpants, with oil.

Heavily soiled clothing and oil-impregnated footwear should not be worn. Overalls must be cleaned regu-
larly.

First aid treatment should be obtained immediately for open cuts and wounds.

Use barrier creams, applying them before each work period, to help the removal of oil from the skin.

Wash with soap and water to ensure all oil is removed (skin cleansers and nail brushes will help). Prepa-
rations containing lanolin replace the natural skin oils which have been removed.

Do not use gasoline, kerosene, diesel fuel, gas oil, thinners or solvents for cleaning skin.

If skin disorders develop, obtain medical advice without delay.

Where practical, degrease components prior to handling.

Where there is a risk of eye contact, eye protection should be worn, for example, chemical goggles or face
shields; in addition an eye wash facility should be provided.
Precautions for Air ConditioningEAS0014E
Use an approved refrigerant recovery unit any time the air conditioning system must be discharged. Refer to
ATC-162, "
HFC-134a (R-134a) Service Procedure" for specific instructions.
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HOW TO USE THIS MANUAL
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ComponentsEAS001QX

THE LARGE ILLUSTRATIONS are exploded views (see the following) and contain tightening torques,
lubrication points, section number of the PA R T S C ATA L O G (e.g. SEC. 440) and other information neces-
sary to perform repairs.
The illustrations should be used in reference to service matters only. When ordering parts, refer to the
appropriate PA R T S C ATA L O G .
Components shown in an illustration may be identified by a circled number. When this style of illustration
is used, the text description of the components will follow the illustration.
SYMBOLS
1. Union bolt 2. Copper washer 3. Brake hose
4. Cap 5. Bleed valve 6. Sliding pin bolt
7. Piston seal 8. Piston 9. Piston boot
10. Cylinder body 11. Sliding pin 12. Torque member mounting bolt
13. Washer 14. Sliding pin boot 15. Bushing
16. Torque member 17. Inner shim cover 18. Inner shim
19. Inner pad 20. Pad retainer 21. Pad wear sensor
22. Outer pad 23. Outer shim 24. Outer shim cover
1: PBC (Poly Butyl Cuprysil) grease
or silicone-based grease2: Rubber grease : Brake fluid
Refer to GI section for additional symbol definitions.
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HOW TO USE THIS MANUAL
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How to Follow Trouble DiagnosesEAS0014K
DESCRIPTION
NOTICE:
Trouble diagnoses indicate work procedures required to diagnose problems effectively. Observe the following
instructions before diagnosing.
1.Before performing trouble diagnoses, read the “Preliminary Check”, the “Symptom Chart” or the
“Work Flow”.
2.After repairs, re-check that the problem has been completely eliminated.
3.Refer to Component Parts and Harness Connector Location for the Systems described in each
section for identification/location of components and harness connectors.
4.Refer to the Circuit Diagram for quick pinpoint check.
If you need to check circuit continuity between harness connectors in more detail, such as when a
sub-harness is used, refer to Wiring Diagram in each individual section and Harness Layout in PG
section for identification of harness connectors.
5.When checking circuit continuity, ignition switch should be OFF.
6.Before checking voltage at connectors, check battery voltage.
7.After accomplishing the Diagnostic Procedures and Electrical Components Inspection, make sure
that all harness connectors are reconnected as they were.
HOW TO FOLLOW TEST GROUPS IN TROUBLE DIAGNOSES
1.Work and diagnostic procedure
Start to diagnose a problem using procedures indicated in enclosed test groups.
2.Questions and required results
Questions and required results are indicated in bold type in test group.
The meaning of are as follows:
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HOW TO USE THIS MANUAL
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Reference Area
The 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.
AbbreviationsEAS0014M
The following ABBREVIATIONS are used:
SG I0 92 A
ABBREVIATION DESCRIPTION
A/C Air Conditioner
A/T Automatic Transaxle/Transmission
ATF Automatic Transmission Fluid
D
1Drive range 1st gear
D
2Drive range 2nd gear

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SERVICE INFORMATION FOR ELECTRICAL INCIDENT
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SERVICE INFORMATION FOR ELECTRICAL INCIDENTPFP:00000
How to Check Terminal EAS0014N
CONNECTOR AND TERMINAL PIN KIT
Use the connector and terminal pin kits listed below when replacing connectors or terminals.
The connector and terminal pin kits contain some of the most commonly used NISSAN/INFINITI connectors
and terminals. For detailed connector and terminal pin replacement procedures, refer to the latest NISSAN/
INFINITI CONNECTOR AND TERMINAL PIN SERVICE MANUAL.
HOW TO PROBE CONNECTORS
Connector damage and an intermittent connection can result from improperly probing of the connector during
circuit checks.
The probe of a digital multimeter (DMM) may not correctly fit the connector cavity. To correctly probe the con-
nector, follow the procedures below using a “T” pin. For the best contact grasp the “T” pin using an alligator
clip.
Probing from Harness Side
Standard type (not waterproof type) connector should be probed
from harness side with “T” pin.

If the connector has a rear cover such as a ECM connector,
remove the rear cover before probing the terminal.

Do not probe waterproof connector from harness side. Damage
to the seal between wire and connector may result.
Probing from Terminal Side
FEMALE TERMINAL

There is a small notch above each female terminal. Probe each
terminal with the “T” pin through the notch.
Do not insert any object other than the same type male terminal
into female terminal.
Tool number
(Kent-Moore No.)
Tool nameDescription
-
(J38751-95NI)
Connector and terminal
pin kit (NISSAN)
-
(J38751-95INF)
Connector and terminal
pin kit (INFINITI)
-
(J42992-98KIT)
OBD and terminal repair
kit
-
(J42992-2000UPD)
OBD-II Connector Kit Up-
date
WAIA0004EWAIA0005E
SGI841
SEL265V

SERVICE INFORMATION FOR ELECTRICAL INCIDENT
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How to Perform Efficient Diagnosis for an Electrical IncidentEAS0014O
WORK FLOW
INCIDENT SIMULATION TESTS
Introduction
Sometimes 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 fol-
lowing 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:

Vehicle vibration

Heat sensitive
SG I8 38
STEP DESCRIPTION
STEP 1Get 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/Transaxle 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 2Operate the system, road test if necessary.
Verify the parameter of the incident.
If the problem cannot be duplicated, refer to “Incident Simulation Tests”.
STEP 3Get the proper diagnosis materials together including:

Power Supply Routing

System Operation Descriptions

Applicable Service Manual Sections

Check for any Service Bulletins
Identify where to begin diagnosis based upon your knowledge of the system operation and the customer comments.
STEP 4Inspect 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 6Operate the system in all modes. Verify the system works properly under all conditions. Make sure you have not inad-
vertently created a new incident during your diagnosis or repair steps.

SERVICE INFORMATION FOR ELECTRICAL INCIDENT
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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 possible damage or
pinching.
Heat Sensitive
The customer's concern 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 60°C (140°F). If incident occurs
while heating the unit, either replace or properly insulate the compo-
nent.
Freezing
The customer may indicate the incident goes away after the car
warms up (winter time). The cause could be related to water freezing
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 outside
overnight. In the morning, do a quick and thorough diagnosis of
those electrical components which could be affected.
The second method is to put the suspect component into a freezer
long enough for any water to freeze. Reinstall the part into the car
and check for the reoccurrence of the incident. If it occurs, repair or
replace the component.
Water Intrusion
The incident may occur only during high humidity or in rainy/snowy
weather. In such cases the incident could be caused by water intru-
sion on an electrical part. This can be simulated by soaking the car
or running it through a car wash.
Do not spray water directly on any electrical components.
Electrical Load
The incident may be electrical load sensitive. Perform diagnosis with
all accessories (including A/C, rear window defogger, radio, fog
lamps) turned on.
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SERVICE INFORMATION FOR ELECTRICAL INCIDENT
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If repairs are needed always use wire that is of the same or larger gauge.
MEASURING VOLTAGE DROP — ACCUMULATED METHOD

Connect the DMM across the connector or part of the circuit you want to check. The positive lead of the
DMM should be closer to power and the negative lead closer to ground.

Operate the circuit.

The DMM will indicate how many volts are being used to “push” current through that part of the circuit.
Note in the illustration that there is an excessive 4.1 volt drop between the battery and the bulb.
MEASURING VOLTAGE DROP — STEP-BY-STEP
The step-by-step method is most useful for isolating excessive drops in low voltage systems (such as those in
“Computer Controlled Systems”).
Circuits in the “Computer Controlled System” operate on very low amperage.
The (Computer Controlled) system operations can be adversely affected by any variation in resistance in the
system. Such resistance variation may be caused by poor connection, improper installation, improper wire
gauge or corrosion.
The step by step voltage drop test can identify a component or wire with too much resistance.
SG I9 74
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