INFINITI QX4 2005 Factory Service Manual

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HOW TO USE THIS MANUAL
Revision: October 20052005 QX56

A line with regular weight (wider line) represents a “detectable
line for DTC (Diagnostic Trouble Code)”. A “detectable line for
DTC” is a circuit in which ECM can detect its malfunctions with
the on board diagnostic system.

A line with less weight (thinner line) represents a “non-detect-
able line for DTC”. A “non-detectable line for DTC” is a circuit in
which ECM cannot detect its malfunctions with the on board
diagnostic system.
Multiple Switch
The continuity of multiple switch is described in two ways as shown below.

The switch chart is used in schematic diagrams.
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The switch diagram is used in wiring diagrams.
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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.
AbbreviationsEAS001FL
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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Revision: October 20052005 QX56D3Drive range 3rd gear
D
4Drive range 4th gear
FR, RR Front, Rear
LH, RH Left-Hand, Right-Hand
M/T Manual Transaxle/Transmission
OD Overdrive
P/S Power Steering
SAE Society of Automotive Engineers, Inc.
SDS Service Data and Specifications
SST Special Service Tools
2WD 2-Wheel Drive
2
22nd range 2nd gear
2
12nd range 1st gear
1
21st range 2nd gear
1
11st range 1st gear ABBREVIATION DESCRIPTION

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SERVICE INFORMATION FOR ELECTRICAL INCIDENT
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SERVICE INFORMATION FOR ELECTRICAL INCIDENTPFP:00000
How to Check Terminal EAS001FM
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
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Some connectors do not have a notch above each terminal. To
probe each terminal, remove the connector retainer to make
contact space for probing.
MALE TERMINAL
Carefully probe the contact surface of each terminal using a “T” pin.
Do not bend terminal.
How to Check Enlarged Contact Spring of Terminal
An enlarged contact spring of a terminal may create intermittent signals in the circuit.
If the intermittent open circuit occurs, follow the procedure below to inspect for open wires and enlarged con-
tact spring of female terminal.
1. Assemble a male terminal and approx. 10 cm (3.9 in) of wire.
Use a male terminal which matches the female terminal.
2. Disconnect the suspected faulty connector and hold it terminal
side up.
3. While holding the wire of the male terminal, try to insert the male
terminal into the female terminal.
Do not force the male terminal into the female terminal with
your hands.
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SEL267V
SEL270V
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4. While moving the connector, check whether the male terminal
can be easily inserted or not.

If the male terminal can be easily inserted into the female termi-
nal, replace the female terminal.
Waterproof Connector Inspection
If water enters the connector, it can short interior circuits. This may lead to intermittent problems.
Check the following items to maintain the original waterproof characteristics.
RUBBER SEAL INSPECTION

Most waterproof connectors are provided with a rubber seal
between the male and female connectors. If the seal is missing,
the waterproof performance may not meet specifications.

The rubber seal may come off when connectors are discon-
nected. Whenever connectors are reconnected, make sure the
rubber seal is properly installed on either side of male or female
connector.
WIRE SEAL INSPECTION
The wire seal must be installed on the wire insertion area of a waterproof connector. Be sure that the seal is
installed properly.
Terminal Lock Inspection
Check for unlocked terminals by pulling wire at the end of connector.
An unlocked terminal may create intermittent signals in the circuit.
SEL272V
SEL273V
SEL275V
SEL330V

SERVICE INFORMATION FOR ELECTRICAL INCIDENT
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How to Perform Efficient Diagnosis for an Electrical IncidentEAS001FN
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.

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Freezing

Water intrusion

Electrical load

Cold 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 Vibration
The 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 following illustra-
tion.
CONNECTORS & HARNESS
Determine which connectors and wiring harness would affect the electrical system you are inspecting. Gently
shake each connector and harness while monitoring the system for the incident you are trying to duplicate.
This test may indicate a loose or poor electrical connection.
HINT
Connectors can be exposed to moisture. It is possible to get a thin film of corrosion on the connector termi-
nals. A visual inspection may not reveal this without disconnecting the connector. If the problem occurs inter-
mittently, 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
Gently apply 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.
ENGINE COMPARTMENT
There are several reasons a vehicle or engine vibration could cause an electrical complaint. Some of the
things to check for are:

Connectors not fully seated.

Wiring harness not long enough and is being stressed due to engine vibrations or rocking.

Wires laying across brackets or moving components.

Loose, dirty or corroded ground wires.

Wires routed too close to hot components.
To inspect components under the hood, start by verifying the integrity of ground connections. (Refer to Ground
Inspection described later.) First check that the system is properly grounded. Then check for loose connection
by gently shaking the 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. Vehi-
cle vibration can aggravate a harness which is routed along a bracket or near a screw.
UNDER SEATING AREAS
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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.
Cold or Hot Start Up
On some occasions an electrical incident may occur only when the car is started cold, or it may occur when
the car is restarted hot shortly after being turned off. In these cases you may have to keep the car overnight to
make a proper diagnosis.
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