INFINITI QX56 2008 Factory Service Manual

HA-46
< ON-VEHICLE REPAIR >
REFRIGERANT PRESSURE SENSOR
REFRIGERANT PRESSURE SENSOR
Removal and Installation for Refrigerant Pressure SensorINFOID:0000000001516660
REMOVAL
1. Discharge the refrigerant. Refer to HA-20, "HFC-134a (R-134a) Service Procedure".
2. Disconnect the refrigerant pressure sensor electrical connector and remove the refrigerant pressure sensor from the condenser.
CAUTION:
Be careful not to damage the condenser fins.
INSTALLATION
Installation is in the reverse order of removal.
Refer to HA-29, "
Component".
CAUTION:
• Be careful not to damage the condenser fins.
• Replace the O-ring of the refriger ant pressure sensor with a new one, then apply compressor oil to it
when installing it.
• After charging refrigerant, check for leaks.
LJIA0145E
Revision: March 2010 2008 QX56

EXPANSION VALVEHA-47
< ON-VEHICLE REPAIR >
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EXPANSION VALVE
Removal and Installation for Front Expansion ValveINFOID:0000000001516661
REMOVAL
1. Discharge the refrigerant. Refer to HA-20, "HFC-134a (R-134a) Service Procedure".
2. Remove the front evaporator. Refer to VTL-35, "
Removal and Installation for Front Evaporator".
3. Remove the cooler grommet.
4. Remove the expansion valve.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
• Replace the O-rings on the A/C refrigerant pipes with new ones, th en apply compressor oil to them
when installing them.
• After charging refrigerant, check for leaks.
WJIA0582E
Expansion valve bolts : 4 N·m (0.41 kg-m, 35 in-lb)
A/C refrigerant pipe to expansion valve bolt : Refer to HA-29, "
Component".
Revision: March 2010 2008 QX56

HA-48
< SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS)
Service Data and Specification (SDS)INFOID:0000000001516662
COMPRESSOR
OIL
REFRIGERANT
Make ZEXEL VALEO CLIMATE CONTROL
Model DKS-17D
Ty p e Swash plate
Displacement 175.5 cm
3 (10.7 in3 ) / revolution
Cylinder bore × stroke 30.5 mm (1.20 in) x 24.0 mm (0.94 in)
Direction of rotation Clockwise (viewed from drive end)
Drive belt Poly V
Name NISSAN A/C System Oil Type S
Capacity 290 m (9.8 US fl oz, 10.2 Imp fl oz)
Ty p eHFC 134a (R-134a)
Capacity 1.08 ± 0.05 kg (2.38 ± 0.11 lb)
Revision: March 2010 2008 QX56

HAC-1
VENTILATION, HEATER & AIR CONDITIONER
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CONTENTS
HEATER & AIR CONDITIONING CONTROL SYSTEM
AUTOMATIC AIR CONDITIONER
BASIC INSPECTION ....... .............................
3
DIAGNOSIS AND REPAIR WORKFLOW ..... .....3
How to Perform Trouble Diagnosis For Quick And
Accurate Repair ........................................................
3
INSPECTION AND ADJUSTMENT ................ .....4
Operational Check (Front) ................................... ......4
Operational Check (Rear) .........................................5
FUNCTION DIAGNOSIS ...............................7
FUNCTION INFORMATION ........................... .....7
Component Part Location ................................... ......7
Symptom Table .........................................................9
REFRIGERATION SYSTEM ..............................11
Refrigerant Cycle ................................................ ....11
Refrigerant System Protection ................................11
AUTOMATIC AIR CONDITIONER SYSTEM . ....12
Control System Diagram ..................................... ....12
Control System Description .....................................12
Discharge Air Flow (Front) ......................................15
Discharge Air Flow (Rear) .......................................15
Switches And Their Control Function (Front) ..........17
Switches And Their Control Function (Rear) ...........18
CAN COMMUNICATION SYSTEM ....................19
System Description ............................................. ....19
DIAGNOSIS SYSTEM (HVAC) ..........................20
CONSULT-III Function (HVAC) ........................... ....20
DIAGNOSIS SYSTEM (BCM) ............................21
CONSULT-III Function (BCM) ............................. ....21
SELF-DIAGNOSIS FUNCTION ..........................22
A/C Auto Amp. Self-Diagnosis ................................22
A/C and AV Switch Asse mbly Self-Diagnosis .........22
A/C System Self-Diagnosis Code Chart .............. ....23
COMPONENT DIAGNOSIS .........................24
MODE DOOR MOTOR ......................................24
System Description .............................................. ....24
Mode Door Motor (Front) Component Function
Check ......................................................................
25
Mode Door Motor (Front) Diagnosis Procedure ......26
AIR MIX DOOR MOTOR ...................................30
System Description ..................................................30
Air Mix Door Motor Component Function Check .....31
Air Mix Door Motor (Driver) Diagnosis Procedure ....32
Air Mix Door Motor (Passenger) Diagnosis Proce-
dure .........................................................................
35
INTAKE DOOR MOTOR ...................................40
System Description ..................................................40
Intake Door Motor Component Function Check ......41
Intake Door Motor Diagnosis Procedure .................42
DEFROSTER DOOR MOTOR CIRCUIT ...........44
System Description ..................................................44
Defroster Door Motor Component Function Check
....
45
Defroster Door Motor Diagnosis Procedure ............45
BLOWER MOTOR CONTROL SYSTEM ..........49
System Description ..................................................49
Front Blower Motor Component Function Check ....50
Front Blower Motor Diagnosis Procedure ................51
Front Blower Motor Component Inspection .............54
Rear Blower Motor Description ................................55
Rear Blower Motor Component Function Check .....56
Rear Air Control (Front) Diagnosis Procedure #1 ....57
Rear Air Control (Rear) Diagnosis Procedure #2 ....58
Rear Blower Motor Component Inspection ..............59
REAR AIR CONTROL SYSTEM .......................61
Rear Air Control System Description .......................61
Rear Air Control Component Function Check .........61
Air Mix Door Motor (Rear) Diagnosis Procedure .....62
Mode Door Motor (Rear) Diagnosis Procedure .......66
Revision: March 2010 2008 QX56

HAC-2
MAGNET CLUTCH ............................................71
System Description .............................................. ...71
Magnet Clutch Component Function Check ........ ...71
Magnet Clutch Diagnosis Procedure ................... ...72
WATER VALVE CIRCUIT ..................................76
Description ........................................................... ...76
Water Valve Diagnosis Procedure ..........................76
AMBIENT SENSOR ...........................................78
Component Description ....................................... ...78
Ambient Sensor Diagnosis Procedure ....................78
Ambient Sensor Component Inspection .................79
IN-VEHICLE SENSOR .......................................81
Component Description ....................................... ...81
In-Vehicle Sensor Diagnosis Procedure .................81
In-Vehicle Sensor Component Inspection ..............83
OPTICAL SENSOR ...........................................84
Component Description ..........................................84
Optical Sensor Diagnosis Procedure ......................84
INTAKE SENSOR ..............................................86
System Description .............................................. ...86
Intake Sensor Diagnosis Procedure .......................86
Intake Sensor Component Inspection ................. ...87
POWER SUPPLY AND GROUND CIRCUIT
FOR CONTROLLER ..........................................
88
Component Description ....................................... ...88
A/C Auto Amp. Component Function Check ..........88
A/C Auto Amp Power and Ground Diagnosis Pro-
cedure .....................................................................
89
ECU DIAGNOSIS .......................................90
AIR CONDITIONER CONTROL ..................... ...90
A/C Auto Amp. Terminals Reference Values ..........90
Wiring Diagram .................................................... ...92
SYMPTOM DIAGNOSIS ...........................108
AIR CONDITIONER CONTROL ..................... ..108
Symptom Matrix Chart ........................................ .108
INSUFFICIENT COOLING ................................109
Component Function Check ................................ .109
Diagnostic Work Flow ...........................................110
Performance Chart ................................................113
Trouble Diagnoses for Abnormal Pressure ...........114
INSUFFICIENT HEATING ................................117
Component Function Check .................................117
NOISE ...............................................................119
Component Function Check ................................ .119
MEMORY FUNCTION DOES NOT OPERATE ..121
Memory Function Check ...................................... .121
PRECAUTION ...........................................122
PRECAUTIONS .............................................. ..122
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" .............................................................. .
122
Working with HFC-134a (R-134a) ........................ .122
Precaution for Service Equipment ........................123
Revision: March 2010 2008 QX56

DIAGNOSIS AND REPAIR WORKFLOWHAC-3
< BASIC INSPECTION > [AUTOMATIC AIR CONDITIONER]
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BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
How to Perform Trouble Diagnosis For Quick And Accurate RepairINFOID:0000000001679763
WORK FLOW
1.LISTEN TO CUSTOMER COMPLAINT
Listen to customer complaint. Get detailed information about the conditions and environment when the symp-
tom occurs.
>> GO TO 2
2.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 3.
3.VERIFY THE SYMPTOM WITH OPERATIONAL CHECK
Verify the symptom with operational check. Refer to HAC-4, "
Operational Check (Front)".
Can a symptom be duplicated?
YES >> GO TO 4
NO >> GO TO 5
4.GO TO APPROPRIATE TROUBLE DIAGNOSIS
Go to appropriate trouble diagnosis. Refer to HAC-108, "
SymptomMatrixChart".
Can a symptom be duplicated?
>> GO TO 5.
5.PERFORM THE A/C AUTO AMP SELF-DIAGNOSIS
Perform A/C auto amp. self-diagnosis. Refer to HAC-22, "
A/C Auto Amp. Self-Diagnosis".
>> If any diagnostic trouble codes set. Refer to HAC-23, "
A/C System Self-Diagnosis Code Chart".
>> Confirm the repair by perform ing operational check. Refer to HAC-4, "
Operational Check (Front)".
Revision: March 2010 2008 QX56

HAC-4
< BASIC INSPECTION >[AUTOMATIC AIR CONDITIONER]
INSPECTION AND ADJUSTMENT
INSPECTION AND ADJUSTMENT
Operational Check (Front)INFOID:0000000001679764
The purpose of the operational check is to
confirm that the system operates properly.
CHECKING MEMORY FUNCTION
1. Set the temperature to 32 °C (90 °F).
2. Press the OFF switch.
3. Turn ignition switch OFF.
4. Turn ignition switch ON.
5. Press the AUTO switch.
6. Confirm that the set temperature remains at previous temperature.
7. Press the OFF switch.
If NG, go to trouble diagnosis procedure for HAC-121, "
Memory Function Check".
If OK, continue with next check.
CHECKING BLOWER
1. Press the blower speed control switch (+) once, blower should operate on low speed. The fan display should have one bar lit (on display).
2. Press the blower speed control switch (+) again, and continue checking blower speed and fan display until
all speeds are checked.
3. Leave blower on maximum speed.
If NG, go to trouble diagnosis procedure for HAC-51, "
Front Blower Motor Diagnosis Procedure".
If OK, continue with next check.
CHECKING DISCHARGE AIR
1. Press MODE switch four times and the DEF switch.
2. Each position indicator should change shape (on display).
3. Confirm that discharge air comes out according to the air distribution table. Refer to HAC-15, "
Discharge
Air Flow (Front)".
Mode door position is checked in the next step.
If NG, go to trouble diagnosis procedure for HAC-26, "
Mode Door Motor (Front) Diagnosis Procedure".
If OK, continue the check.
NOTE:
Confirm that the compressor clutch is engaged (sound or visual inspection) and intake door position is at
fresh when the DEF or D/F is selected.
CHECKING RECIRCULATION ( , ONLY)
1. Press recirculation ( ) switch one time. Recirculation indicator should illuminate.
2. Press recirculation ( ) switch one more time. Recirculation indicator should go off.
3. Listen for intake door position change (blower sound should change slightly).
If NG, go to trouble diagnosis procedure for HAC-42, "
Intake Door Motor Diagnosis Procedure".
If OK, continue the check.
NOTE:
Confirm that the compressor clutch is engaged (sound or vis ual inspection) and intake door position is at fresh
when the DEF or D/F is selected. REC ( ) is not allowed in DEF ( ) D/F ( ) or FOOT ( ).
CHECKING TEMPERATURE DECREASE
1. Rotate temperature control dial (drive or passenger) counterclockwise until 18° C (60°F) is displayed.
2. Check for cold air at appropriate discharge air outlets. Conditions : Engine running and at normal operating temperature
Revision: March 2010
2008 QX56

INSPECTION AND ADJUSTMENTHAC-5
< BASIC INSPECTION > [AUTOMATIC AIR CONDITIONER]
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If NG, listen for sound of air mix door motor operat ion. If OK, go to trouble diagnosis procedure for HAC-109,
"Component Function Check". If air mix door motor appears to be malfunctioning, go to HAC-31, "Air Mix Door
Motor Component Function Check".
If OK, continue the check.
CHECKING TEMPERATURE INCREASE
1. Rotate temperature control dial clockwise (drive or passenger) 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 operat ion. If OK, go to trouble diagnosis procedure for HAC-117,
"Component Function Check". If air mix door motor appears to be malfunctioning, go to HAC-31, "Air Mix Door
Motor Component Function Check".
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).
NOTE:
If current mode setting is DEF or D/F, compre ssor clutch will already be engaged and cannot be turned off.
If NG, go to trouble diagnosis procedure for HAC-72, "
Magnet Clutch Diagnosis Procedure".
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 temperat ure is cool, confirm that the compressor clutch
engages (sound or visual inspection). (Discharge air and blower speed will depend on ambient, in-vehi-
cle, and set temperatures.)
If NG, go to trouble diagnosis procedure for HAC-89, "
A/C Auto Amp Power and Ground Diagnosis Proce-
dure", then if necessary, trouble diagnosis procedure for HAC-72, "Magnet Clutch Diagnosis Procedure".
If all operational checks are OK (symptom cannot be duplicated), go to malfunction Simulation Tests in HAC-
3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair" and perform tests as outlined to simu-
late driving conditions environment. If symptom appears. Refer to HAC-108, "
SymptomMatrixChart", and
perform applicable troubl e diagnosis procedures.
Operational Check (Rear)INFOID:0000000001679765
The purpose of the operational check is to confirm that the system operates properly.
CHECKING REAR BLOWER MOTOR
1. Turn the ignition switch ON.
2. Rotate rear air control (front) blower control dial to low speed.
3. Rotate the blower control dial clockwise and continue checking blower speed until all speeds are checked.
4. Leave blower on maximum speed.
5. Press the REAR CTRL switch from the rear air control (front).
6. Rotate rear air control (rear) blower control dial to low speed.
7. Rotate the blower control dial clockwise and continue checking blower speed until all speeds are checked.
8. Leave blower on maximum speed.
If NG, go to trouble diagnosis procedure for HAC-56, "
Rear Blower Motor Component Function Check".
If OK, continue with next check.
CHECKING REAR DISCHARGE AIR
Conditions : Engine running and at normal operating temperature
Revision: March 2010 2008 QX56

HAC-6
< BASIC INSPECTION >[AUTOMATIC AIR CONDITIONER]
INSPECTION AND ADJUSTMENT
1. The REAR CTRL indicator must be off. Press each rear air con-
trol (front) mode door switches and confirm the discharge air
comes out relative to the icon on each switch and according to
the air distribution table. Refer to HAC-15, "
Discharge Air Flow
(Rear)".
2. Press the REAR CTRL switch (indicator on) from the rear air control (front).
3. Press each rear air control (rear) mode door switches and con-
firm the discharge air comes out relative to the icon on each
switch and according to the air distribution table. Refer to HAC-
15, "Discharge Air Flow (Rear)".
Air mix door position is checked in the next step.
If NG, go to HAC-31, "
Air Mix Door Motor Component Function
Check".
If OK, continue with next check.
CHECKING REAR TEMPERATURE DECREASE
1. Press the REAR CTRL switch (indicator off).
2. Rotate the rear air control (front) temperatur e control dial counterclockwise to maximum cold.
3. Check for cold air at appropriate discharge air outlets.
4. Press the REAR CTRL switch (indicator on) from the rear air control (front).
5. Rotate the rear air control (rear) temperature control dial counterclockwise to maximum cold.
6. 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 HAC-31,
"Air Mix Door Motor Component Function Check". If air mix door motor appears to be malfunctioning, go to
HAC-62, "
Air Mix Door Motor (Rear) Diagnosis Procedure".
If OK, continue with next check.
CHECKING REAR TEMPERATURE INCREASE
1. Press the REAR CTRL switch (indicator off).
2. Rotate the rear air control (front) temperature control dial clockwise to maximum heat.
3. Check for hot air at appropriate discharge air outlets.
4. Press the REAR CTRL switch (indictor on) from the rear air control (front).
5. Rotate the rear air control (rear) temperature control dial clockwise to maximum heat.
6. 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 HAC-31,
"Air Mix Door Motor Component Function Check". If air mix door motor appears to be malfunctioning, go to
HAC-62, "
Air Mix Door Motor (Rear) Diagnosis Procedure".
If NG, go to trouble diagnosis procedure for HAC-117, "
Component Function Check".
If all operational checks are OK (symptom cannot be duplicated), go to HAC-3, "
How to Perform Trouble Diag-
nosis For Quick And Accurate Repair" and perform tests as outlined. If symptom appears, refer to HAC-108,
"SymptomMatrixChart" and perform applicable trouble diagnosis procedures.
WJIA0541E
Revision: March 2010 2008 QX56

FUNCTION INFORMATIONHAC-7
< FUNCTION DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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FUNCTION DIAGNOSIS
FUNCTION INFORMATION
Component Part LocationINFOID:0000000001679766
ENGINE COMPARTMENT
WJIA1912E
1. Water valve F68 2. Refrigerant pressure sensor E48 3. Ambient sensor E1
4. A/C compressor F3
Revision: March 2010 2008 QX56