heating INFINITI QX4 2005 Factory Service Manual

ATC-2Revision: October 20052005 QX56 SWITCHES AND THEIR CONTROL FUNCTION ... 31
CAN Communication System Description .............. 32
TROUBLE DIAGNOSIS ............................................ 33
CONSULT-II Function (HVAC) ................................ 33
CONSULT-II BASIC OPERATION ....................... 33
SELF-DIAGNOSIS .............................................. 34
DATA MONITOR .................................................. 34
CONSULT-II Function (BCM) .................................. 36
CONSULT-II BASIC OPERATION ....................... 36
DATA MONITOR .................................................. 37
How to Perform Trouble Diagnosis for Quick and
Accurate Repair ...................................................... 38
WORK FLOW ...................................................... 38
SYMPTOM TABLE .............................................. 38
Component Parts and Harness Connector Location ... 39
ENGINE COMPARTMENT .................................. 39
FRONT PASSENGER COMPARTMENT ............ 40
REAR PASSENGER COMPARTMENT ............... 41
Schematic ............................................................... 42
Wiring Diagram — A/C,A — ................................... 43
Front Air Control Terminals and Reference Value ... 53
PIN CONNECTOR TERMINAL LAYOUT ............ 53
TERMINALS AND REFERENCE VALUE FOR
FRONT AIR CONTROL ....................................... 53
A/C System Self-diagnosis Function ...................... 55
DESCRIPTION .................................................... 55
Operational Check (Front) ...................................... 57
CHECKING MEMORY FUNCTION ..................... 57
CHECKING BLOWER ......................................... 57
CHECKING DISCHARGE AIR ............................ 58
CHECKING RECIRCULATION ............................ 58
CHECKING TEMPERATURE DECREASE ......... 58
CHECKING TEMPERATURE INCREASE .......... 59
CHECK A/C SWITCH .......................................... 59
CHECKING AUTO MODE ................................... 59
Operational Check (Rear) ....................................... 60
CHECKING BLOWER ......................................... 60
CHECKING TEMPERATURE DECREASE ......... 60
CHECKING TEMPERATURE INCREASE .......... 60
Power Supply and Ground Circuit for Front Air Con-
trol ........................................................................... 61
INSPECTION FLOW ........................................... 61
COMPONENT DESCRIPTION ............................ 62
DIAGNOSTIC PROCEDURE FOR A/C SYSTEM ... 62
Mode Door Motor Circuit ........................................ 64
INSPECTION FLOW ........................................... 64
SYSTEM DESCRIPTION .................................... 65
COMPONENT DESCRIPTION ............................ 66
DIAGNOSTIC PROCEDURE FOR MODE
DOOR MOTOR ................................................... 66
Air Mix Door Motor Circuit ...................................... 70
INSPECTION FLOW ........................................... 70
SYSTEM DESCRIPTION .................................... 71
COMPONENT DESCRIPTION ............................ 72
DIAGNOSTIC PROCEDURE FOR AIR MIX
DOOR MOTOR (DRIVER) ................................... 72
DIAGNOSTIC PROCEDURE FOR AIR MIX
DOOR MOTOR (PASSENGER) .......................... 76
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR (REAR) ......................................79
Intake Door Motor Circuit ........................................83
INSPECTION FLOW ............................................83
SYSTEM DESCRIPTION .....................................84
COMPONENT DESCRIPTION ............................85
DIAGNOSTIC PROCEDURE FOR INTAKE
DOOR MOTOR ....................................................85
Defroster Door Motor Circuit ...................................87
SYMPTOM: ..........................................................87
INSPECTION FLOW ............................................87
SYSTEM DESCRIPTION .....................................88
COMPONENT DESCRIPTION ............................88
DIAGNOSTIC PROCEDURE FOR
DEFROSTER DOOR MOTOR .............................89
Front Blower Motor Circuit ......................................93
INSPECTION FLOW ............................................93
SYSTEM DESCRIPTION .....................................94
COMPONENT DESCRIPTION ............................95
DIAGNOSTIC PROCEDURE FOR BLOWER
MOTOR ................................................................95
COMPONENT INSPECTION ............................. 100
Rear Blower Motor Circuit ..................................... 101
INSPECTION FLOW .......................................... 101
SYSTEM DESCRIPTION ................................... 102
DIAGNOSTIC PROCEDURE FOR REAR
BLOWER MOTOR ............................................. 102
COMPONENT INSPECTION .............................110
Rear Air Control Circuit .........................................112
INSPECTION FLOW ..........................................112
SYSTEM DESCRIPTION ...................................113
DIAGNOSTIC PROCEDURE FOR REAR AIR
CONTROL .........................................................113
Magnet Clutch Circuit ............................................115
INSPECTION FLOW ..........................................115
SYSTEM DESCRIPTION ...................................116
DIAGNOSTIC PROCEDURE FOR MAGNET
CLUTCH ............................................................116
Insufficient Cooling ................................................ 121
INSPECTION FLOW .......................................... 121
PERFORMANCE TEST DIAGNOSES .............. 122
PERFORMANCE CHART .................................. 124
TROUBLE DIAGNOSES FOR UNUSUAL PRES-
SURE ................................................................. 125
Insufficient Heating ............................................... 128
INSPECTION FLOW .......................................... 128
Noise ..................................................................... 129
INSPECTION FLOW .......................................... 130
Self-diagnosis ....................................................... 132
INSPECTION FLOW .......................................... 132
Memory Function .................................................. 133
INSPECTION FLOW .......................................... 133
Water Valve Circuit ................................................ 133
COMPONENT DESCRIPTION .......................... 133
DIAGNOSTIC PROCEDURE FOR WATER
VALVE ................................................................ 134
COMPONENT INSPECTION ............................. 136
Ambient Sensor Circuit ......................................... 137
COMPONENT DESCRIPTION .......................... 137
AMBIENT TEMPERATURE INPUT PROCESS . 137

ATC-38
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
How to Perform Trouble Diagnosis for Quick and Accurate RepairEJS003XF
WORK FLOW
SYMPTOM TABLE
*1AT C - 5 7 , "Operational Check (Front)"
or ATC-60, "
Operational Check
(Rear)" .
SHA9 00 E
Symptom Reference Page
A/C system does not come on. Go to Trouble Diagnosis Procedure for A/C System.AT C - 6 1
A/C system display is malfunctioning. Go to Navigation SystemAV- 6 1
A/C system cannot be controlled. Go to Self-diagnosis Function.AT C - 5 5
Air outlet does not change.
Go to Trouble Diagnosis Procedure for Mode Door Motor.AT C - 6 4
Mode door motor is malfunctioning.
Discharge air temperature does not change.
Go to Trouble Diagnosis Procedure for Air Mix Door Motor.AT C - 7 0
Air mix door motor is malfunctioning.
Intake door does not change.
Go to Trouble Diagnosis Procedure for Intake Door Motor.AT C - 8 3
Intake door motor is malfunctioning.
Defroster door motor is malfunctioning. Go to Trouble Diagnosis Procedure for Defroster Door Motor.AT C - 8 7
Front blower motor operation is malfunction-
ing.Go to Trouble Diagnosis Procedure for Front Blower Motor.AT C - 9 3
Rear blower motor operation is malfunction-
ing.Go to Trouble Diagnosis Procedure for Rear Blower Motor.AT C - 1 0 1
Rear discharge air temperature and/or air
outlet does not change.Go to Trouble Diagnosis Procedure for Rear Air Control circuit.AT C -11 2
Magnet clutch does not engage. Go to Trouble Diagnosis Procedure for Magnet Clutch.AT C -11 5
Insufficient cooling Go to Trouble Diagnosis Procedure for Insufficient Cooling.AT C - 1 2 1
Insufficient heating Go to Trouble Diagnosis Procedure for Insufficient Heating.AT C - 1 2 8
Noise Go to Trouble Diagnosis Procedure for Noise.AT C - 1 2 9
Self-diagnosis cannot be performed. Go to Trouble Diagnosis Procedure for Self-diagnosis.AT C - 1 3 2
Memory function does not operate. Go to Trouble Diagnosis Procedure for Memory Function.AT C - 1 3 3

TROUBLE DIAGNOSIS
ATC-59
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AT C
Revision: October 20052005 QX56
CHECKING TEMPERATURE INCREASE
1. Rotate temperature control dial clockwise (driver side or passen-
ger side) until 32°C (90°F) is displayed.
2. Check for hot air at appropriate discharge air outlets.
If NG, listen for sound of air mix door motor operation. If OK, go to
trouble diagnosis procedure for ATC-128, "
Insufficient Heating" . If
air mix door motor appears to be malfunctioning, go to AT C - 7 2 ,
"DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR
(DRIVER)" or AT C - 7 6 , "DIAGNOSTIC PROCEDURE FOR AIR MIX
DOOR MOTOR (PASSENGER)" .
If OK, continue with next check.
CHECK A/C SWITCH
1. Press A/C switch when AUTO switch is ON, or in manual mode.
2. A/C switch indicator will turn ON.

Confirm that the compressor clutch engages (sound or visual
inspection).
If NG, go to trouble diagnosis procedure for AT C - 11 5
.
If OK, continue with next check.
CHECKING AUTO MODE
1. Press AUTO switch.
2. Display should indicate AUTO.

If ambient temperature is warm, and selected temperature is
cool, confirm that the compressor clutch engages (sound or
visual inspection). (Discharge air and blower speed will
depend on ambient, in-vehicle, and set temperatures.)
If NG, go to trouble diagnosis procedure for ATC-61, "
Power Supply
and Ground Circuit for Front Air Control" , then if necessary, trouble
diagnosis procedure for ATC-115, "
Magnet Clutch Circuit" .
If all operational checks are OK (symptom cannot be duplicated), go
to malfunction Simulation Tests in ATC-38, "
How to Perform Trouble
Diagnosis for Quick and Accurate Repair" and perform tests as out-
lined to simulate driving conditions environment. If symptom appears. Refer to AT C - 3 8 , "
How to Perform Trou-
ble Diagnosis for Quick and Accurate Repair" , ATC-38, "SYMPTOM TABLE" and perform applicable trouble
diagnosis procedures.
WJIA1048E
WJIA1049E
WJIA1043E

ATC-60
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
Operational Check (Rear)EJS003XM
The purpose of the operational check is to confirm that the system operates properly.
CHECKING BLOWER
1. Turn the rear blower control dial to switch position "1". Blower
should operate on low speed.
2. Turn the rear blower control dial counterclockwise to switch
position "2", "3", and "4" until all speeds are checked.
3. Leave blower on MAX speed.
If NG, go to trouble diagnosis procedure for ATC-101, "
Rear Blower
Motor Circuit" .
If OK, continue the check.
CHECKING TEMPERATURE DECREASE
1. Rotate temperature and mode dial fully counterclockwise.
2. Check for cold air at appropriate discharge air outlets.
If NG, listen for sound of air mix door motor operation if OK, go to
trouble diagnosis procedure for ATC-121, "
Insufficient Cooling" . If
air mix door motor appears to be malfunctioning, go to ATC-79,
"DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR
(REAR)" .
If OK, continue the check.
CHECKING TEMPERATURE INCREASE
1. Rotate temperature and mode dial clockwise.
2. Check for hot air at appropriate discharge air outlets.
If NG, listen for sound of air mix door motor operation. If OK, go to
trouble diagnosis procedure for ATC-128, "
Insufficient Heating" . If
air mix door motor appears to be malfunctioning, go to ATC-79,
"DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR
(REAR)" .
If OK, continue the check.Conditions : Engine running and at normal operating temperature
WJIA1350E
WJIA1069E
WJIA1070E

ATC-128
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
Insufficient HeatingEJS003XX
SYMPTOM: Insufficient heating
INSPECTION FLOW
*1ATC-57, "Operational Check (Front)"
or ATC-60, "
Operational Check
(Rear)"
*2AT C - 7 0 , "Air Mix Door Motor Circuit"*3AT C - 5 5 , "A/C System Self-diagno-
sis Function"
*4ATC-56, "SELF-DIAGNOSIS CODE
CHART"
*5AT C - 9 3 , "Front Blower Motor Circuit"*6EC-195, "DTC P0117, P0118 ECT
SENSOR"
*7EM-12, "Checking Drive Belts"*8ATC-133, "Water Valve Circuit"
WJIA1372E

BL-190
BODY REPAIR
Revision: October 20052005 QX56
Precautions in Repairing High Strength SteelEIS008SM
High strength steel is used for body panels in order to reduce vehicle weight.
Accordingly, precautions in repairing automotive bodies made of high strength steel are described below:
HIGH STRENGTH STEEL (HSS) USED IN NISSAN VEHICLES
SP130 is the most commonly used HSS.
SP150 HSS is used only on parts that require much more strength.
Read the following precautions when repairing HSS:
1. Additional points to consider

The repair of reinforcements (such as side members) by heat-
ing is not recommended since it may weaken the component.
When heating is unavoidable, do not heat HSS parts above
550°C (1,022°F).
Verify heating temperature with a thermometer.
(Crayon-type and other similar type thermometer are appro-
priate.)

When straightening body panels, use caution in pulling any
HSS panel. Because HSS is very strong, pulling may cause
deformation in adjacent portions of the body. In this case,
increase the number of measuring points, and carefully pull
the HSS panel.

When cutting HSS panels, avoid gas (torch) cutting if possi-
ble. Instead, use a saw to avoid weakening surrounding areas
due to heat. If gas (torch) cutting is unavoidable, allow a mini-
mum margin of 50 mm (1.97in).
Tensile strength Nissan/Infiniti designation Major applicable parts
373 N/mm
2
(38kg/mm2 ,54klb/sq in)SP130

Front inner pillar upper

Front pillar hinge brace

Outer front pillar reinforcement

Other reinforcements
785-981 N/mm
2
(80-100kg/mm2
114-142klb/sq in)SP150

Outer sill reinforcement

Main back pillar
PIIA0115E
PIIA0116E
PIIA0117E

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

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

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

CO-20Revision: October 2005
THERMOSTAT AND WATER PIPING
2005 QX56
CAUTION:
Perform when the engine is cold.
2. Remove the air duct and resonator assembly. Refer to EM-14, "
REMOVAL" .
3. Remove the engine room cover using power tool.
4. Disconnect the heater hose (heater core side).
5. Remove the heater hose bracket.
6. Disconnect the water cut valve connector.
7. Remove the water cut valve.
INSPECTION AFTER REMOVAL

Place a thread so that it is caught in the valve of the thermostat.
Immerse fully in a container filled with water. Heat while stirring.

The valve opening temperature is the temperature at which the
valve opens and falls from the thread.

Continue heating. Check the full-open lift amount.

After checking the full-open lift amount, lower the water temper-
ature and check the valve closing temperature.
Standard values:
INSTALLATION
Installation is in the reverse order of removal.
Installation of Thermostat

Install the thermostat with the whole circumference of each
flange part fit securely inside the rubber ring as shown.

Install the thermostat with the jiggle valve facing upwards.
Installation of Water Outlet Pipe and Heater Pipe
First apply a neutral detergent to the O-rings, then quickly insert the insertion parts of the water outlet pipe and
heater pipe into the installation holes.
INSPECTION AFTER INSTALLATION

Check for leaks of the engine coolant. Refer to CO-10, "CHECKING COOLING SYSTEM FOR LEAKS" .

Start and warm up the engine. Visually check for leaks of the engine coolant.
SL C2 52 B
Thermostat
Valve opening temperature 80 - 84°C (176 - 183° F)
Full-open lift amount More than 10 mm/ 95°C (0.39 in/ 203°F)
Valve closing temperature 77°C (171°F) or higher
KBIA2502E