2004 INFINITI QX56 fuse

CYLINDER HEAD
EM-59
C
D
E
F
G
H
I
J
K
L
MA
EM
Revision: August 20072004 QX56
CYLINDER HEADPFP:11041
On-Vehicle ServiceEBS00ILS
CHECKING COMPRESSION PRESSURE
1. Warm up engine thoroughly. Then stop engine.
2. Release fuel pressure. Refer to EC-46, "
FUEL PRESSURE RELEASE" .
a. Remove fuel pump fuse, and start engine.
Refer to PG-78, "
FUSE AND RELAY BOX" or fuel pump fuse location.

Let fuel pump fuse removed until the end of step 7.
b. After engine stalls, crank it two or three times to release all fuel pressure.
3. Remove ignition coil and spark plug from each cylinder.
Refer to EM-27, "
REMOVAL" .
4. Connect engine tachometer (not required in use of CONSULT-II).
5. Install compression tester with Tool into spark plug hole.
6. With accelerator pedal fully depressed, turn ignition switch to “START” for cranking. When the gauge
pointer stabilizes, read the compression pressure and engine rpm. Perform these steps to check each cyl-
inder.
Unit: kPa (kg/cm2 , psi) /rpm
CAUTION:
Always use a fully charged battery to obtain specified engine speed.

If the engine speed is out of specified range, check battery liquid for proper gravity. Check engine
speed again with normal battery gravity.

If compression pressure is below minimum value, check valve clearances and parts associated with
combustion chamber (valve, valve seat, piston, piston ring, cylinder bore, cylinder head, cylinder head
gasket). After the checking, measure compression pressure again.

If some cylinders have low compression pressure, pour small amount of engine oil into the spark plug
hole of the cylinder to re-check it for compression.
–If the added engine oil improves the compression, the piston rings may be worn out or damaged. Check
the piston rings and replace if necessary.
–If the compression pressure remains at low level despite the addition of engine oil, the valves may be
malfunctioning. Check the valves for damage. Replace the valve or valve seat accordingly.

If two adjacent cylinders have respectively low compression pressure and their compression remains
low even after the addition of engine oil, the gaskets may be leaking, or valve in adjacent cylinders may
be damaged. Inspect and repair as required.
7. After inspection is complete, install removed parts. Installation is in the reverse order of removal.
8. Start engine, and confirm that engine runs smoothly.
9. Perform trouble diagnosis. If DTC appears, erase it. Refer to EC-71, "
TROUBLE DIAGNOSIS" . Tool number : EG15050500 (J-45402)
WBIA0605E
Standard MinimumDeference limit
between cylinders
1,520 (15.5, 220) / 200 1,324 (13.5, 192) / 200 98 (1.0, 14) / 300

ENGINE ASSEMBLY
EM-71
C
D
E
F
G
H
I
J
K
L
MA
EM
Revision: August 20072004 QX56
5. Remove the cowl extension. Refer to EI-18, "Removal and Installation" .
6. Remove engine room cover using power tools.
7. Remove the air duct and air cleaner case assembly. Refer to EM-14, "
REMOVAL" .
8. Disconnect vacuum hose between vehicle and engine and set it aside.
9. Remove the radiator assembly and hoses. Refer to CO-10, "
REMOVAL" .
10. Remove the drive belts. Refer to EM-12, "
Removal" .
11. Remove the fan blade. Refer to CO-13, "
REMOVAL" .
12. Disconnect the engine room harness from the fuse box and set it aside for easier work.
13. Disconnect the ECM.
14. Disconnect the engine room harness from the engine side and set it aside for easier work.
15. Disconnect the engine harness grounds.
16. Disconnect the reservoir tank for power steering from engine and move it aside for easier work.
17. Disconnect power steering oil pump from engine. Move it from its location and secure with a rope for eas-
ier work. Refer to PS-26, "
REMOVAL" .
18. Remove the A/C compressor bolts and set aside. Refer to ATC-166, "
REMOVAL" .
19. Disconnect brake booster vacuum line.
20. Disconnect EVAP line.
21. Disconnect the fuel hose at the engine side connection. Refer to EM-29, "
REMOVAL" .
22. Disconnect the heater hoses at cowl, and install plugs to avoid leakage of engine coolant.
23. Remove the A/T oil level indicator and indicator tube upper bolts.
24. Remove the A/T. Refer to AT-255, "
Removal and Installation (4x2)" , or AT-258, "Removal and Installation
(4x4)" .
25. Install engine slingers into left bank cylinder head and right bank
cylinder head.
26. Lift with hoist and secure the engine in position.
27. Remove engine assembly from vehicle, avoiding interference
with vehicle body.
CAUTION:

Before and during this lifting, always check if any har-
nesses are left connected.
28. Remove alternator. Refer to SC-27, "
REMOVAL" .
29. Remove engine mounting insulator and bracket using power tool.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:

When replacing an engine or transmission you must make sure the dowels are installed correctly
during re-assembly.

Improper alignment caused by missing dowels may cause vibration, oil leaks or breakage of driv-
etrain components.
WBIA0464E
Engine slinger torque: 45.0 N·m (4.6 kg-m, 33 ft-lb)
PBIC1556E

CYLINDER BLOCK
EM-85
C
D
E
F
G
H
I
J
K
L
MA
EM
Revision: August 20072004 QX56
Undersize Bearings Usage Guide

When the specified oil clearance is not obtained with standard size connecting rod bearings, use under-
size (US) bearings.

When using undersize bearing, measure the bearing inside diameter with bearing installed, and grind the
crankshaft pin so that the oil clearance satisfies the standard.
Bearing undersize table
Unit: mm (in)
CAUTION:
In grinding the crankshaft pin to use undersize bearings, keep
the fillet R (All crankshaft pins).
HOW TO SELECT MAIN BEARING
When New Cylinder Block and Crankshaft are Used
1. Apply main bearing housing grade on bottom face of cylinder
block to the row in the "Main Bearings Selection Table".
2. Apply journal diameter grade on crankshaft front to the column
in the "Main Bearings Selection Table".
3. Read the symbol at the cross point of selected row and column in the "Main Bearings Selection Table".
CAUTION:

Initial clearance for No.1, 5 journal and No. 2, 3, 4 journal is different. Use two different selection
lists for each part.

No.1, 5 journal and No. 2, 3, 4 journal have the same signs but different measures. Do not con-
fuse.
4. Apply the symbol to the "Main Bearings Grade Table" to select.
NOTE:

Grade list applies to all journals.

Service parts are available as a set of both upper and lower.
2 1.506 - 1.509 (0.0593 - 0.0594) Green
3 1.509 - 1.512 (0.0594 - 0.0595) Yellow
Undersize Thickness
0.25 (0.0098) 1.627 - 1.635 (0.0641 - 0.0644)
Fillet R : 1.5 - 1.7 mm (0.059 - 0.067 in)
PB I C 0 111E
KBIA2495E
PBIC0 110 E

FRONT FINAL DRIVE ASSEMBLY
FFD-19
C
E
F
G
H
I
J
K
L
MA
B
FFD
Revision: August 20072004 QX56
11. Keep the side bearing outer races together with inner race. Do
not mix them up.
12. Remove side bearing inner race.
To prevent damage to bearing, engage puller jaws in groove.
CAUTION:

To prevent damage to the side bearing and drive gear,
place copper plates between these parts and vise.

It is not necessary to remove side bearing except it is
replaced.

Be careful not to confuse left-hand and right-hand parts.
Keep bearing and bearing race for each side together.
13. Loosen drive gear bolts in a crisscross fashion.
14. Tap drive gear off the differential case with a soft hammer.

Tap evenly all around to keep the drive gear from bending.
15. Drive out pinion mate shaft lock pin with suitable punch from
drive gear side.
SPD5 27
Tool number A: ST33081000 ( — )
B: ST30021000 ( — )
SDIA2237E
SPD0 22
SDIA2238E
SPD0 25

HOW TO USE THIS MANUAL
GI-17
C
D
E
F
G
H
I
J
K
L
MB
GI
Revision: August 20072004 QX56
Optional Splice
DESCRIPTION
SG I9 42
Num-
berItem Description
1 Power condition

This shows the condition when the system receives battery positive voltage (can be oper-
ated).
2 Fusible link

The double line shows that this is a fusible link.

The open circle shows current flow in, and the shaded circle shows current flow out.
3Fusible link/fuse loca-
tion

This shows the location of the fusible link or fuse in the fusible link or fuse box. For arrange-
ment, refer to PG section, POWER SUPPLY ROUTING.
4Fuse

The single line shows that this is a fuse.

The open circle shows current flow in, and the shaded circle shows current flow out.
5 Current rating

This shows the current rating of the fusible link or fuse.
6 Connectors

This shows that connector E3 is female and connector M1 is male.

The G/R wire is located in the 1A terminal of both connectors.

Terminal number with an alphabet (1A, 5B, etc.) indicates that the connector is SMJ connec-
tor. Refer to PG section, SMJ (SUPER MULTIPLE JUNCTION).
7 Optional splice

The open circle shows that the splice is optional depending on vehicle application.
8 Splice

The shaded circle shows that the splice is always on the vehicle.
9 Page crossing

This arrow shows that the circuit continues to an adjacent page.

The A will match with the A on the preceding or next page.
10 Common connector

The dotted lines between terminals show that these terminals are part of the same connector.
11 Option abbreviation

This shows that the circuit is optional depending on vehicle application.
12 Relay

This shows an internal representation of the relay. For details, refer to PG section, STAN-
DARDIZED RELAY.
13 Connectors

This shows that the connector is connected to the body or a terminal with bolt or nut.

GI-18
HOW TO USE THIS MANUAL
Revision: August 20072004 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
SERVICE INFORMATION FOR ELECTRICAL INCIDENT
Revision: August 20072004 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.
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.
SG I8 46 -A

SERVICE INFORMATION FOR ELECTRICAL INCIDENT
GI-31
C
D
E
F
G
H
I
J
K
L
MB
GI
Revision: August 20072004 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).
SG I8 47 -A