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BRC-70
[VDC/TCS/ABS]
G SENSOR
Revision: October 20052005 QX56
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CO-1
ENGINE COOLING SYSTEM
B ENGINE
CONTENTS
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SECTION CO
A
CO
Revision: October 20052005 QX56 PRECAUTIONS .......................................................... 2
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 2
Precautions for Liquid Gasket .................................. 2
REMOVAL OF LIQUID GASKET SEALING .......... 2
LIQUID GASKET APPLICATION PROCEDURE ..... 2
PREPARATION ........................................................... 4
Special Service Tools ............................................... 4
Commercial Service Tools ........................................ 4
OVERHEATING CAUSE ANALYSIS .......................... 6
Troubleshooting Chart .............................................. 6
COOLING SYSTEM .................................................... 8
Cooling Circuit .......................................................... 8
System Drawing ....................................................... 9
ENGINE COOLANT .................................................. 10
Inspection ............................................................... 10
LEVEL CHECK ................................................... 10
CHECKING COOLING SYSTEM FOR LEAKS ... 10
CHECKING RESERVOIR CAP ........................... 10
CHECKING RADIATOR CAP .............................. 10
Changing Engine Coolant ...................................... 10
DRAINING ENGINE COOLANT ......................... 10
REFILLING ENGINE COOLANT .........................11
FLUSHING COOLING SYSTEM ..........................11
RADIATOR ................................................................ 12
Removal and Installation ........................................ 12
REMOVAL ........................................................... 12
INSTALLATION ................................................... 14INSPECTION AFTER INSTALLATION ................ 14
Checking Radiator .................................................. 14
ENGINE COOLING FAN ........................................... 15
Removal and Installation (Crankshaft Driven Type) ... 15
REMOVAL ........................................................... 15
INSPECTION AFTER REMOVAL ....................... 15
INSTALLATION ................................................... 15
INSPECTION AFTER INSTALLATION ................ 15
Removal and Installation (Motor Driven Type) ....... 16
REMOVAL ........................................................... 16
INSTALLATION ................................................... 16
WATER PUMP .......................................................... 17
Removal and Installation ........................................ 17
REMOVAL ........................................................... 17
INSPECTION AFTER REMOVAL ....................... 17
INSTALLATION ................................................... 17
INSPECTION AFTER INSTALLATION ................ 18
THERMOSTAT AND WATER PIPING ...................... 19
Removal and Installation ........................................ 19
REMOVAL ........................................................... 19
INSPECTION AFTER REMOVAL ....................... 20
INSTALLATION ................................................... 20
INSPECTION AFTER INSTALLATION ................ 20
SERVICE DATA AND SPECIFICATIONS (SDS) ...... 21
Standard and Limit .................................................. 21
ENGINE COOLANT CAPACITY (APPROXI-
MATE) .................................................................. 21
THERMOSTAT .................................................... 21
RADIATOR .......................................................... 21
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CO-2Revision: October 2005
PRECAUTIONS
2005 QX56
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
EBS00LMZ
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WAR NIN G:
To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.
Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.
Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
Precautions for Liquid GasketEBS00NII
REMOVAL OF LIQUID GASKET SEALING
After removing the bolts and nuts, separate the mating surface
and remove the old liquid gasket sealing using Tool.
CAUTION:
Do not damage the mating surfaces.
Tap the seal cutter to insert it.
In areas where the Tool is difficult to use, lightly tap to slide it.
LIQUID GASKET APPLICATION PROCEDURE
1. Remove the old liquid gasket adhering to the gasket application
surface and the mating surface using suitable tool.
Remove the liquid gasket completely from the groove of the
liquid gasket application surface, bolts, and bolt holes.
2. Thoroughly clean the mating surfaces and remove adhering
moisture, grease and foreign material.Tool number : KV10111100 (J-37228)
WBIA0566E
PBIC0003E
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PRECAUTIONS
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Revision: October 20052005 QX56
3. Attach the liquid gasket tube to the Tool.
Use Genuine RTV Silicone Sealant or equivalent. Refer to
GI-45, "
Recommended Chemical Products and Sealants" .
4. Apply the liquid gasket without breaks to the specified location
with the specified dimensions.
If there is a groove for the liquid gasket application, apply the
liquid gasket to the groove.
As for the bolt holes, normally apply the liquid gasket inside
the holes. If specified in the procedure, it should also be
applied outside the holes.
Within five minutes of liquid gasket application, install the mat-
ing component.
If the liquid gasket protrudes, wipe it off immediately.
Do not retighten after the installation.
Wait 30 minutes or more after installation before refilling the
engine with engine oil and engine coolant.
CAUTION:
If there are specific instructions in this manual, observe them.Tool number : WS39930000 ( — )
WBIA0567E
SEM 15 9F
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CO-4Revision: October 2005
PREPARATION
2005 QX56
PREPARATIONPFP:00002
Special Service ToolsEBS00LN0
The actual shapes of Kent-Moore tools may differ from those of special service tools illustrated here.
Commercial Service ToolsEBS00LN1
Tool number
(Kent-Moore No.)
Tool nameDescription
KV10111100
(J-37228)
Seal cutterRemoving steel oil pan and rear timing chain
case
WS39930000
(—)
Tube pressurePressing the tube of liquid gasket
EG17650301
(J-33984-A)
Radiator cap tester adapterAdapting radiator cap tester to radiator cap
and radiator filler neck
a: 28 (1.10) dia.
b: 31.4 (1.236) dia.
c: 41.3 (1.626) dia.
Unit: mm (in)
—
(J-23688)
Engine coolant refractometerChecking concentration of ethylene glycol in
engine coolant
NT046
S-NT052
S-NT564
W BIA0539E
Tool nameDescription
Power toolLoosening bolts and nuts
Radiator cap tester Checking radiator and radiator cap
PBIC0190E
PBIC1982E
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PREPARATION
CO-5
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Revision: October 20052005 QX56
Coolant system tester adapter Adapting radiator cap tester to reservoir filler
neck
Coolant system tester adapter Adapting radiator cap tester to reservoir cap Tool nameDescription
W BIA0408E
W BIA0409E
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CO-6Revision: October 2005
OVERHEATING CAUSE ANALYSIS
2005 QX56
OVERHEATING CAUSE ANALYSISPFP:00012
Troubleshooting ChartEBS00LN2
Symptom Check items
Cooling sys-
tem parts
malfunctionPoor heat transferWater pump malfunction Worn or loose drive belt
— Thermostat stuck closed —
Damaged finsDust contamination or
paper clogging
Physical damage
Clogged radiator cooling
tubeExcess foreign material
(rust, dirt, sand, etc.)
Water cut valve malfunctionExcess foreign material
(rust, dirt, sand, etc.), phys-
ical damage
Reduced air flowCooling fan does not oper-
ate
Fan assembly — High resistance to fan rota-
tion
Damaged fan blades
Damaged radiator shroud — — —
Improper engine coolant
mixture ratio—— —
Poor engine coolant quality — Engine coolant density —
Insufficient engine coolantEngine coolant leaksCooling hoseLoose clamp
Cracked hose
Water pump Poor sealing
Radiator capLoose
Poor sealing
RadiatorO-ring for damage, deterio-
ration or improper fitting
Cracked radiator tank
Cracked radiator core
Reservoir tank Cracked reservoir tank
Overflowing reservoir tankExhaust gas leaks into
cooling systemCylinder head deterioration
Cylinder head gasket dete-
rioration
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OVERHEATING CAUSE ANALYSIS
CO-7
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Revision: October 20052005 QX56
Except cool-
ing system
parts mal-
function— Overload on engineAbusive drivingHigh engine rpm under no
load
Driving in low gear for
extended time
Driving at extremely high
speed
Powertrain system mal-
function
— Installed improper size
wheels and tires
Dragging brakes
Improper ignition timing
Blocked or restricted air
flowBlocked bumper —
— Blocked radiator grilleInstalled car brassiere
Mud contamination or
paper clogging
Blocked radiator —
Blocked condenser
Blocked air flow
Installed large fog lamp Symptom Check items