2005 INFINITI QX4 fuse

GI-18
HOW TO USE THIS MANUAL
Revision: October 20052005 QX56
14 Wire color

This 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 or O = Orange
P = Pink
PU or V (Violet) = Purple
GY or GR = 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 description

This shows a description of the option abbreviation used on the page.
16 Switch

This shows that continuity exists between terminals 1 and 2 when the switch is in the A posi-
tion. Continuity exists between terminals 1 and 3 when the switch is in the B position.
17 Assembly parts

Connector terminal in component shows that it is a harness incorporated assembly.
18 Cell code

This identifies each page of the wiring diagram by section, system and wiring diagram page
number.
19 Current flow arrow

Arrow indicates electric current flow, especially where the direction of standard flow (vertically
downward or horizontally from left to right) is difficult to follow.

A double arrow “ ” shows that current can flow in either direction depending on cir-
cuit operation.
20 System branch

This shows that the system branches to another system identified by cell code (section and
system).
21 Page crossing

This arrow shows that the circuit continues to another page identified by cell code.

The C will match with the C on another page within the system other than the next or preced-
ing pages.
22 Shielded line

The line enclosed by broken line circle shows shield wire.
23Component box in
wave line

This shows that another part of the component is also shown on another page (indicated by
wave line) within the system.
24 Component name

This shows the name of a component.
25 Connector number

This shows the connector number.

The letter shows which harness the connector is located in.

Example: M : main harness. For detail and to locate the connector, refer to PG section "Main
Harness", “Harness Layout”. A coordinate grid is included for complex harnesses to aid in
locating connectors.
26 Ground (GND)

The line spliced and grounded under wire color shows that ground line is spliced at the
grounded connector.
27 Ground (GND)

This shows the ground connection. For detailed ground distribution information, refer to
"Ground Distribution" in PG section.
28 Connector views

This area shows the connector faces of the components in the wiring diagram on the page.
29 Common component

Connectors enclosed in broken line show that these connectors belong to the same compo-
nent.
30 Connector color

This 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
box

This shows the arrangement of fusible link(s) and fuse(s), used for connector views of
"POWER SUPPLY ROUTING" in PG section.
The open square shows current flow in, and the shaded square shows current flow out.
32 Reference area

This shows that more information on the Super Multiple Junction (SMJ) and Joint Connectors
(J/C) exists on the PG section. Refer to "Reference Area" for details. Num-
berItem Description

GI-30
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CIRCUIT INSPECTION
Introduction
In general, testing electrical circuits is an easy task if it is approached in a logical and organized method.
Before beginning it is important to have all available information on the system to be tested. Also, get a thor-
ough understanding of system operation. Then you will be able to use the appropriate equipment and follow
the correct test procedure.
You may have to simulate vehicle vibrations while testing electrical components. Gently shake the wiring har-
ness or electrical component to do this.
NOTE:
Refer to “How to Check Terminal” to probe or check terminal.
Testing for “Opens” in the Circuit
Before you begin to diagnose and test the system, you should rough sketch a schematic of the system. This
will help you to logically walk through the diagnosis process. Drawing the sketch will also reinforce your work-
ing knowledge of the system.
CONTINUITY CHECK METHOD
The continuity check is used to find an open in the circuit. The digital multimeter (DMM) set on the resistance
function will indicate an open circuit as over limit (no beep tone or no ohms symbol). Make sure to always start
with the DMM at the highest resistance level.
To help in understanding the diagnosis of open circuits, please refer to the previous schematic.

Disconnect the battery negative cable.

Start at one end of the circuit and work your way to the other end. (At the fuse block in this example)

Connect one probe of the DMM to the fuse block terminal on the load side.

Connect the other probe to the fuse block (power) side of SW1. Little or no resistance will indicate that
portion of the circuit has good continuity. If there were an open in the circuit, the DMM would indicate an
over limit or infinite resistance condition. (point A)

Connect the probes between SW1 and the relay. Little or no resistance will indicate that portion of the cir-
cuit has good continuity. If there were an open in the circuit, the DMM would indicate an over limit or infi-
nite resistance condition. (point B)

Connect the probes between the relay and the solenoid. Little or no resistance will indicate that portion of
the circuit has good continuity. If there were an open in the circuit, the DMM would indicate an over limit or
infinite resistance condition. (point C)
Any circuit can be diagnosed using the approach in the previous example.
VOLTAGE CHECK METHOD
To help in understanding the diagnosis of open circuits please refer to the previous schematic.
In any powered circuit, an open can be found by methodically checking the system for the presence of voltage.
This is done by switching the DMM to the voltage function.
OPENA circuit is open when there is no continuity through a section of the circuit.
SHORTThere are two types of shorts.

SHORT CIRCUITWhen a circuit contacts another circuit and causes the normal resistance to
change.

SHORT TO GROUND When a circuit contacts a ground source and grounds the circuit.
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SERVICE INFORMATION FOR ELECTRICAL INCIDENT
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Connect one probe of the DMM to a known good ground.

Begin probing at one end of the circuit and work your way to the other end.

With SW1 open, probe at SW1 to check for voltage.
voltage; open is further down the circuit than SW1.
no voltage; open is between fuse block and SW1 (point A).

Close SW1 and probe at relay.
voltage; open is further down the circuit than the relay.
no voltage; open is between SW1 and relay (point B).

Close the relay and probe at the solenoid.
voltage; open is further down the circuit than the solenoid.
no voltage; open is between relay and solenoid (point C).
Any powered circuit can be diagnosed using the approach in the previous example.
Testing for “Shorts” in the Circuit
To simplify the discussion of shorts in the system, please refer to the following schematic.
RESISTANCE CHECK METHOD

Disconnect the battery negative cable and remove the blown fuse.

Disconnect all loads (SW1 open, relay disconnected and solenoid disconnected) powered through the
fuse.

Connect one probe of the DMM to the load side of the fuse terminal. Connect the other probe to a known
good ground.

With SW1 open, check for continuity.
continuity; short is between fuse terminal and SW1 (point A).
no continuity; short is further down the circuit than SW1.

Close SW1 and disconnect the relay. Put probes at the load side of fuse terminal and a known good
ground. Then, check for continuity.
continuity; short is between SW1 and the relay (point B).
no continuity; short is further down the circuit than the relay.

Close SW1 and jump the relay contacts with jumper wire. Put probes at the load side of fuse terminal and
a known good ground. Then, check for continuity.
continuity; short is between relay and solenoid (point C).
no continuity; check solenoid, retrace steps.
VOLTAGE CHECK METHOD

Remove the blown fuse and disconnect all loads (i.e. SW1 open, relay disconnected and solenoid discon-
nected) powered through the fuse.

Turn the ignition key to the ON or START position. Verify battery voltage at the battery + side of the fuse
terminal (one lead on the battery + terminal side of the fuse block and one lead on a known good ground).

With SW1 open and the DMM leads across both fuse terminals, check for voltage.
voltage; short is between fuse block and SW1 (point A).
no voltage; short is further down the circuit than SW1.

With SW1 closed, relay and solenoid disconnected and the DMM leads across both fuse terminals, check
for voltage.
voltage; short is between SW1 and the relay (point B).
SG I8 47 -A

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SERVICE INFORMATION FOR ELECTRICAL INCIDENT
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no voltage; short is further down the circuit than the relay.

With SW1 closed, relay contacts jumped with fused jumper wire check for voltage.
voltage; short is down the circuit of the relay or between the relay and the disconnected solenoid (point C).
no voltage; retrace steps and check power to fuse block.
Ground Inspection
Ground connections are very important to the proper operation of electrical and electronic circuits. Ground
connections are often exposed to moisture, dirt and other corrosive elements. The corrosion (rust) can
become an unwanted resistance. This unwanted resistance can change the way a circuit works.
Electronically controlled circuits are very sensitive to proper grounding. A loose or corroded ground can drasti-
cally affect an electronically controlled circuit. A poor or corroded ground can easily affect the circuit. Even
when the ground connection looks clean, there can be a thin film of rust on the surface.
When inspecting a ground connection follow these rules:

Remove the ground bolt or screw.

Inspect all mating surfaces for tarnish, dirt, rust, etc.

Clean as required to assure good contact.

Reinstall bolt or screw securely.

Inspect for “add-on” accessories which may be interfering with the ground circuit.

If several wires are crimped into one ground eyelet terminal, check for proper crimps. Make sure all of the
wires are clean, securely fastened and providing a good ground path. If multiple wires are cased in one
eyelet make sure no ground wires have excess wire insulation.
For detailed ground distribution information, refer to “Ground Distribution” in PG section.
Voltage Drop Tests
Voltage drop tests are often used to find components or circuits which have excessive resistance. A voltage
drop in a circuit is caused by a resistance when the circuit is in operation.
Check the wire in the illustration. When measuring resistance with DMM, contact by a single strand of wire will
give reading of 0 ohms. This would indicate a good circuit. When the circuit operates, this single strand of wire
is not able to carry the current. The single strand will have a high resistance to the current. This will be picked
up as a slight voltage drop.
Unwanted resistance can be caused by many situations as follows:

Undersized wiring (single strand example)

Corrosion on switch contacts

Loose wire connections or splices.
If repairs are needed always use wire that is of the same or larger gauge.
MEASURING VOLTAGE DROP — ACCUMULATED METHOD
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POWER WINDOW SYSTEM
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POWER WINDOW SYSTEMPFP:25401
Component Parts and Harness Connector LocationEIS005XN
System DescriptionEIS005XO
Power is supplied at all time

from 50A fusible link (letter f , located in the fuse and fusible link box)

to BCM terminal 70

through BCM terminal 69

to main power window and door lock/unlock switch terminal 19

to power window and door lock/unlock switch RH terminal 10.
With ignition switch in ON or START position,
Power is supplied

through 10A fuse (No. 59, located in the fuse and relay box)

to BCM terminal 38

through BCM terminal 68

to main power window and door lock/unlock switch terminal 10.

to rear power vent window relays (OPEN and CLOSE) terminal 1.
With ignition switch in ON or START position,
Ground is supplied

to BCM terminal 67

to main power window and door lock/unlock switch terminal 17

to power window and door lock/unlock switch RH terminal 11

through body grounds M57, M61 and M79.
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POWER WINDOW SYSTEM
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BCM Power Supply and Ground Circuit CheckEIS005XY
1. CHECK FUSE AND FUSIBLE LINK

Check 10A fuse (No. 4, located in the fuse block (J/B)]

Check 10A fuse (No. 59, located in the fuse and relay box)

Check 50A fusible link (letter f located in the fuse and fusible link box)
NOTE:
Refer to GW-15, "
Component Parts and Harness Connector Location" .
OK or NG
OK >> GO TO 2.
NG >> If fuse is blown, be sure to eliminate cause of malfunction before installing new fuse. Refer to PG-
3, "PRECAUTIONS" .
2. CHECK POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between BCM connector M18, M20 terminals 38, 70 and ground.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace harness.
3. CHECK GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect BCM.
3. Check continuity between BCM connector M20 terminal 67 and ground.
OK or NG
OK >> Power supply and ground circuit is OK.
NG >> Repair or replace harness.38 (W/L) - Ground : Battery voltage
70 (W/B) - Ground : Battery voltage
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67 (B) - Ground : Continuity should exist.
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REAR WINDOW DEFOGGER
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REAR WINDOW DEFOGGERPFP:25350
Component Parts and Harness Connector LocationEIS005YM
System DescriptionEIS005YN
The rear window defogger system is controlled by BCM (body control module) and IPDM E/R (intelligent
power distribution module engine room).
The rear window defogger operates only for approximately 15 minutes.
Power is supplied at all times

through 15A fuses (No. 43, 46, and 47 located in the IPDM E/R)

to rear window defogger relay and heated mirror relay (located in the IPDM E/R)

through 50A fusible link (letter f , located in the fuse and fusible link box)

to BCM terminal 70.
With the ignition switch turned to ON or START position,
Power is supplied

through ignition switch

to rear window defogger relay (located in the IPDM E/R)

through 10A fuse (No. 59, located in the fuse and relay box)

to BCM terminal 38

through 10A fuse [No. 8, located in the fuse block (J/B)]

to front air control terminal 14.
Ground is supplied

to BCM terminal 67

to front air control terminal 1
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REAR WINDOW DEFOGGER
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BCM Power Supply and Ground Circuit CheckEIS005YW
1. CHECK FUSES AND FUSIBLE LINK

Check 10A fuse (No. 8, located in the fuse block (J/B)]

Check 10A fuse (No. 59, located in the fuse and relay box)

Check 50A fusible link (letter f located in the fuse and fusible link box)
NOTE:
Refer to GW-77, "
Component Parts and Harness Connector Location" .
OK or NG
OK >> GO TO 2.
NG >> If fuse is blown, be sure to eliminate cause of malfunction before installing new fuse. Refer to PG-
4, "POWER SUPPLY ROUTING CIRCUIT" .
2. CHECK POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between BCM connector M18, M20 terminals 38, 70
and ground.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace harness.
3. CHECK GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect BCM.
3. Check continuity between BCM connector M20 terminal 67 and ground.
OK or NG
OK >> BCM power supply and ground circuit is OK.
NG >> Repair or replace harness.70 (W/B) - Ground : Battery voltage
38 (W/L) - Ground : Battery voltage
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67 (B) - Ground : Continuity should exist.
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