fuse INFINITI QX56 2006 Factory Service Manual

SERVICE INFORMATION FOR ELECTRICAL INCIDENTGI-31
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Revision: November 2009 2006 QX56
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.
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.
OPEN A circuit is open when there is no continuity through a section of the circuit.
SHORT There are two types of shorts.

SHORT CIRCUIT
When 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.
SGI846-A

GI-32
SERVICE INFORMATION FOR ELECTRICAL INCIDENT
Revision: November 20092006 QX56
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.

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).
SGI847-A

SERVICE INFORMATION FOR ELECTRICAL INCIDENTGI-33
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Revision: November 2009 2006 QX56
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).
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.
SGI853

POWER WINDOW SYSTEMGW-15
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Revision: November 2009 2006 QX56
POWER WINDOW SYSTEMPFP:25401
Component Parts and Harness Connector LocationEIS005XN
1. Fuse block (J/B)2. Fuse and fusible link box3. Fuse and relay box
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GW-16
POWER WINDOW SYSTEM
Revision: November 20092006 QX56
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.
MANUAL OPERATION
Front Door LH
WINDOW UP
When the front LH switch in the main power window and door lock/unlock switch is pressed in the up position,
power is supplied

through main power window and door lock/unlock switch terminal 8

to front power window motor LH terminal 2.
Ground is supplied

through main power window and door lock/unlock switch terminal 11

to front power window motor LH terminal 1.
Then, the motor raises the window until the switch is released.
WINDOW DOWN
When the front LH switch in the main power window and door lock/unlock switch is pressed in the down posi-
tion, power is supplied

through main power window and door lock/unlock switch terminal 11

to front power window motor LH terminal 1.
Ground is supplied

through main power window and door lock/unlock switch terminal 8

to front power window motor LH terminal 2.
Then, the motor lowers the window until the switch is released.
4. A. Steering column B. BCM M18, M19, M20
(View with instrument panel
removed) 5. A. Main power window and door
lock/unlock switch D7, D8
Power window and door lock/unlock
switch RH D105
B. Front door switch LH B8, RH
B108
C. Front power window motor LH
D9, RH D104
D. Front door lock actuator LH (key
cylinder switch) 6. A. Rear power window switch LH
D203, RH D303
B. Rear power window motor LH
D204, RH D304
7. A. Rear power vent window relay (CLOSE)
B. Rear power vent window relay
(OPEN) 8. Rear power vent window switch
R103 9. A. Rear power vent window motor
LH B52, RH B150
B. Condenser-3 B119
Condenser-4 B120

POWER WINDOW SYSTEMGW-37
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Revision: November 2009 2006 QX56
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 BCM POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect BCM.
3. Check voltage between BCM connector and ground.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace the harness.
3. CHECK GROUND CIRCUIT
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.
Connector Terminals
Power
source Condition Voltage (V)
(Approx.)
(+) (-)
M20 70 Ground Battery
power
supply Ignition
switch
OFF Battery voltage
M18 38 Ground
Ignition
power
supply Ignition
switch
ON or
START Battery voltage
11 Ground ACC
power
supply Ignition
switch
ACC or ON Battery voltage
LIIA0995E
67 - Ground
: Continuity should exist.
LIIA0915E

GW-74
REAR WINDOW DEFOGGER
Revision: November 20092006 QX56
REAR WINDOW DEFOGGERPFP:25350
Component Parts and Harness Connector LocationEIS005YM
1. IPDM E/R fuse layout2. Fuse block (J/B) 3. Fuse and fusible link box
4. Fuse and relay box 5. Data link connector M22 6. BCM M18, M20 (View with instru-
ment panel removed)
7. Front air control M49, M50 8. A. Rear window defogger ground
connector D604
B. Rear window defogger connector
D406 9. IPDM E/R E118, E120, E122, E124
10. Door mirror LH D4 Door mirror RH D107
LIIA2329E

REAR WINDOW DEFOGGERGW-75
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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

through body grounds M57, M61 and M79

to IPDM E/R terminals 38 and 59

through body grounds E9, E15 and E24.
When front air control (rear window defogger switch) is turned to ON, ground is supplied

to BCM terminal 9

through front air control terminal 11

through front air control terminal 1

through body grounds M57, M61 and M79.
Then rear window defogger switch is illuminated.
Then BCM recognizes that rear window defogger switch is turned to ON.
Then it sends rear window defogger switch signals to IPDM E/R and display control unit via CAN communica-
tion (CAN-H, CAN-L).
When display control unit receives rear window defogger switch signals, and displays on the screen.
When IPDM E/R receives rear window defogger switch signals, ground is supplied

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

through IPDM E/R terminal 38

through IPDM E/R terminal 59

through body grounds E9, E15 and E24
and then rear window defogger relay is energized.
With power and ground supplied, rear window defogger filaments heat and defog the rear window.
When rear window defogger relay is turned to ON, power is supplied

through heated mirror relay (located in the IPDM E/R)

through IPDM E/R terminal 23

to door mirror defogger (LH and RH) terminal 10.
Door mirror defogger (LH and RH) is grounded through body grounds M57, M61 and M79.
With power and ground supplied, rear window defogger filaments heat and defog the rear window and door
mirror defogger filaments heat and defog the mirror.
CAN Communication System DescriptionEIS005YO
Refer to LAN-26, "CAN COMMUNICATION" .

GW-84
REAR WINDOW DEFOGGER
Revision: November 20092006 QX56
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-74, "
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 - Ground
: Battery voltage
38 - Ground : Battery voltage
LIIA0914E
67 - Ground : Continuity should exist.
LIIA0915E

GW-86
REAR WINDOW DEFOGGER
Revision: November 20092006 QX56
3. CHECK BCM OUTPUT SIGNAL
1. Connect BCM.
2. Turn ignition switch ON.
3. Check voltage between BCM connector M18 terminal 9 and ground.
OK or NG
OK >> Replace front air control. Refer to ATC-144, "FRONT
AIR CONTROL" .
NG >> Replace BCM. Refer to BCS-20, "
BCM" .
Rear Window Defogger Circuit CheckEIS0062Z
1. CHECK FUSES
Check if any of the following fuses in IPDM E/R are blown.
NOTE:
Refer to GW-74, "
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 GW-
74, "Component Parts and Harness Connector Location" .
2. CHECK REAR WINDOW DEFOGGER POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect rear window defogger.
3. Turn ignition switch ON.
4. Check voltage between rear window defogger connector D406 terminal + and ground.
OK or NG
OK >> GO TO 3.
NG >> GO TO 4. 9 - Ground
: Approx. 5
WIIA0523E
COMPONENT PARTS AMPEREFUSE NO.
IPDM E/R 15A46
IPDM E/R 15A47
ConnectorTerminals
ConditionVoltage (V)
(Approx.)
(+) (-)
D406 + Ground Rear window defogger
switch ON.
Battery voltage
Rear window defogger
switch OFF. 0
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