service INFINITI QX56 2008 Factory Service Manual

MODE DOOR MOTORHAC-25
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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The mode door motor (front) is attached to the heater & cooling unit
assembly. It rotates so that air is discharged from the outlet as indi-
cated by the A/C auto amp. Motor rotation is conveyed to a link
which activates the mode door.
Mode Door Motor (Front) Component Function CheckINFOID:0000000001679783
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING O PERATIONAL CHECK - DISCHARGE AIR
1. Press mode switch four times and then press the (DEF) switch. Each position indicator should change shape (on display).
2. Confirm that discharge air comes out accordi ng to the air distribution table. Refer to HAC-15, "
Discharge
Air Flow (Front)".
NOTE:
Confirm that the compressor clutch is engaged (visual inspection) and intake door position is at FRESH
when DEF ( ) or D/F ( ) is selected.
Can a symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.PERFORM COMPLETE OPERATIONAL CHECK
Perform a complete operational check and check for any symptoms. Refer to HAC-4, "
Operational Check
(Front)".
Can a symptom be duplicated?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.CHECK MODE DOOR OPERATION
Check and verify mode door mechanism for smooth operation in each mode.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair as necessary.
5.PERFORM A/C AUTO AMP. SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to HAC-22, "
A/C Auto Amp. Self-Diagnosis".
Are any self-diagnosis codes present?
YES >> Refer to HAC-23, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 6.
6.PERFORM A/C AND AV SWITCH ASSEMBLY SELF-DIAGNOSIS
Perform self-diagnosis to check the A/C and AV switch assembly. Refer to HAC-22, "
A/C and AV Switch
Assembly Self-Diagnosis".
Is the inspection result normal?
YES >> Replace A/C and AV switch assembly. Refer to VTL-7, "Removal and Installation".
NO >> GO TO 7.
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Revision: March 2010 2008 QX56

HAC-32
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
AIR MIX DOOR MOTOR
Perform a complete operational check and check for any symptoms. Refer to
HAC-4, "Operational Check
(Front)".
Can a symptom be duplicated?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> System OK.
4.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 5.
5.CHECK AIR MIX DOOR OPERATION
Check and verify air mix door mechanism for smooth operation from 18 °C (60° F) to 32° C (90°F) in each
mode.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair as necessary.
6.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to HAC-22, "
A/C and AV Switch Assembly Self-Diagno-
sis".
Are any self-diagnosis codes present?
YES >> Refer to HAC-23, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 7.
7.CHECK THE AIR MIX DOOR MOTOR PBR CIRCUIT
Perform diagnostic procedure for the air mix door motors. Refer to HAC-31, "
Air Mix Door Motor Component
Function Check".
Is the inspection result normal?
YES >> GO TO 8.
NO >> Repair PBR circuit or replace air mix door motor. Refer to VTL-26, "
Removal and Installation".
8.RECHECK FOR CODES
Perform self-diagnosis. Refer to HAC-22, "
A/C and AV Switch Assembly Self-Diagnosis".
Are any self-diagnostic codes present?
YES >> Refer to HAC-23, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 9.
9.RECHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to HAC-4, "
Operational Check (Front)".
Does another symptom exist?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
Air Mix Door Motor (Driver) Diagnosis ProcedureINFOID:0000000001679787
SYMPTOM:• Discharge air temperature does not change.
• Air mix door motor does not operate.
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR MOTOR (DRIVER)
1.CHECK A/C AUTO AMP. FOR POWER AND GROUND
Revision: March 2010 2008 QX56

INTAKE DOOR MOTORHAC-41
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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COMPONENT DESCRIPTION
Intake door motor
The intake door motor is attached to the intake unit. It rotates so that
air is drawn from inlets set by the A/C auto amp. Motor rotation is
conveyed to a lever which activates the intake door.
Intake Door Motor Component Function CheckINFOID:0000000001679790
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - REC ( )
1. Press the mode switch to vent mode( ).
2. Press REC ( ) switch. The REC ( )indicator should illuminate.
3. Press REC ( ) switch again. The REC ( ) indicator should go out.
4. Listen for intake door position change (you should hear blower sound change slightly).
Can a symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.PERFORM COMPLETE OPERATIONAL CHECK
Perform a complete operational check and check for any symptoms. Refer to HAC-4, "
Operational Check
(Front)".
Can a symptom be duplicated?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.CHECK INTAKE DOOR OPERATION
Check and verify intake door me chanism for smooth operation.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair intake door mechanism.
5.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to HAC-22, "
A/C and AV Switch Assembly Self-Diagno-
sis".
Are any self-diagnosis codes present?
YES >> Refer to HAC-23, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 6.
6.RECHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to HAC-4, "
Operational Check (Front)".
Does another symptom exist?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> Replace A/C auto amp. Refer to VTL-7, "
Removal and Installation".
WJIA0552E
Revision: March 2010 2008 QX56

DEFROSTER DOOR MOTOR CIRCUITHAC-45
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Defroster Door Motor Co mponent Function CheckINFOID:0000000001679793
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING O PERATIONAL CHECK - DEFROSTER DOOR
1. Press the mode switch and select vent ( ).
2. Press the defrost switch ( ). Defroster indicator should illuminate (on display).
3. Listen for defroster door position change (blower sound should change slightly).
Can the symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to HAC-4, "
Operational Check (Front)".
Does another symptom exist?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> SYSTEM OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.CHECK DEFROSTER DOOR MOTOR
Perform diagnostic procedure for defroster door motor. Refer to HAC-45, "
Defroster Door Motor Component
Function Check".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair PBR circuit or replace defroster door motor. Refer to VTL-21, "
Removal and Installation".
5.CHECK DEFROSTER DOOR OPERATION
Check and verify defroster door mechanism for smooth operation.
Is the inspection result normal?
YES >> Replace defroster door motor. Refer to VTL-21, "Removal and Installation".
NO >> Repair defroster door mechanism.
Defroster Door Motor Diagnosis ProcedureINFOID:0000000001679794
SYMPTOM:
• Defroster door does not change.
• Defroster door motor does not operate normally.
DIAGNOSTIC PROCEDURE FOR DEFROSTER DOOR MOTOR
1.CHECK A/C AUTO AMP. FOR POWER AND GROUND
1. Turn ignition switch ON.
2. Press the defroster switch ( ).
3. Check voltage between A/C auto amp. harness connector M49 terminal 24 and terminal 23 and press the defroster switch ( )
again.
Connector Te r m i n a l s
Condition Voltage
(Approx.)
(+) (-)
A/C auto amp.: M49 24 23 Press de-
froster switch Battery
voltage
AWIIA0152ZZ
Revision: March 2010 2008 QX56

HAC-50
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
BLOWER MOTOR CONTROL SYSTEM
Blower Speed Compensation - Sunload
When the in-vehicle temperature and the set temperature
are very close, the blower will be operating at low
speed. The speed will vary depending on the sunload. During conditions of low or no sunload, the blower
operates at low speed. During high sunload conditions, the A/C auto amp. causes the blower speed to
increase.
Blower Speed Control Specification
COMPONENT DESCRIPTION
Variable Blower Control
The variable blower control is located on the cooling unit. The vari-
able blower control receives a gate voltage from the A/C auto amp.
to steplessly maintain the blower motor voltage in the 0 to 5 volt
range (approx.).
Front Blower Motor Co mponent Function CheckINFOID:0000000001679796
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - FRONT BLOWER
1. Push blower motor (+) switch. Blower motor should operate.
2. Push blower motor (+) switch, and continue checki ng blower speed and fan symbol until all speeds are
checked.
Can the symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to HAC-4, "
Operational Check (Front)".
Does another symptom exist?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.PERFORM A/C AUTO AMP. SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to HAC-22, "
A/C Auto Amp. Self-Diagnosis".
Are any self-diagnosis codes present?
WJIA0441E
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Revision: March 2010 2008 QX56

HAC-56
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
BLOWER MOTOR CONTROL SYSTEM
System Operation
Rear Blower Control
When the rear blower control dial (front) REAR CTRL switch is pressed (indicator on), it allows the rear air
control (rear) to control the rear blower motor speed. If t
he REAR CTRL switch is off (indicator off), the rear air
control (front) controls the rear blower motor s peed regardless of the rear air control (rear) position.
Rear Blower Motor Component Function CheckINFOID:0000000001679800
INSPECTION FLOW
SYMPTOM:
• Rear blower motor does not operate from the rear air control (front) and the rear air control (rear).
• Rear blower motor operates from rear air control (front) only.
• Rear blower motor operates in high at all times.
INSPECTION FLOW
1.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 2.
2.CONFIRM SYMPTOM BY PERFORMING REAR BLOW ER MOTOR OPERATIONAL CHECK FROM REAR
AIR CONTROL (FRONT)
1. Turn ignition switch ON.
2. Turn the rear air control (front) blower control dial to the lowest speed and check for rear blower operation
(REAR CTRL indicator off).
3. Continue checking that rear blower speed increases as the rear blower control dial is rotated clockwise.
Does the rear blower motor operate correctly?
YES >> GO TO 3.
NO >> Check the rear blower motor operation. Refer to HAC-56, "
Rear Blower Motor Component Func-
tion Check".
3.CONFIRM SYMPTOM BY PERFORMING REAR BLOWER MOTOR OPERATIONAL CHECK FROM
REAR AIR CONTROL (REAR)
1. Press the REAR CTRL switch (indicator on) on the rear air control (front) to send control of the rear blower
motor back the rear air control (rear).
2. Turn the rear air control (rear) blower control dial to the lowest speed and check for rear blower operation.
3. Continue checking that rear blower speed increases as the rear blower control dial is rotated clockwise.
Does the rear blower motor operate correctly?
YES >> GO TO 4.
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Revision: March 2010 2008 QX56

REAR AIR CONTROL SYSTEMHAC-61
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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REAR AIR CONTROL SYSTEM
Rear Air Control System DescriptionINFOID:0000000001679804
SYSTEM DESCRIPTION
Component Parts
Rear air control system components are:
• A/C auto amp.
• Rear air control (front)
• Rear air control (rear)
• Air mix door motor (rear)
• Mode door motor (rear)
System Operation
Rear Air Control
When the REAR CTRL indicator is off the rear air cont rol (front) will control all rear blower motor speeds and
the rear temperature and mode operations. When the REAR CTRL switch is pressed (indicator on), the rear
air control (rear) will control all the rear blower motor speeds and the rear temperature and mode operations.
Rear Air Control Component Function CheckINFOID:0000000001679805
SYMPTOM:
• Temperature cannot be adjusted from the rear air controls.
• Mode cannot be adjusted from the rear air controls.
INSPECTION FLOW
1.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 2.
2.CONFIRM SYMPTOM BY PERFORMING REAR AIR CONTROL (FRONT) AIR MIX DOOR MOTOR OP-
ERATIONAL CHECK
AWIIA0197GB
Revision: March 2010 2008 QX56

MAGNET CLUTCHHAC-71
< COMPONENT DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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MAGNET CLUTCH
System DescriptionINFOID:0000000001679808
SYSTEM DESCRIPTION
The A/C auto amp. controls compressor operation based on ambient and intake temperature and a signal
from ECM.
Low Temperature Protection Control
The A/C auto amp. will turn the compressor ON or OFF as determined by a signal detected by the intake sen-
sor and the ambient sensor.
When intake air temperature is higher than the preset value, the compressor turns ON. The compressor turns
OFF when intake air temperature is lower than the pres et value. That preset value is dependent on the ambi-
ent temperature, refer to the following table.
Magnet Clutch Componen t Function CheckINFOID:0000000001679809
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING O PERATIONAL CHECK - MAGNET CLUTCH
1. Turn ignition switch ON.
2. Press the A/C switch.
3. Press vent switch ( ).
4. Display shows , A/C. Confirm that the compress or clutch engages (sound or visual inspection). (Dis-
charge air and blower speed will depend on ambient, in-vehicle and set temperatures.)
Can the symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to HAC-4, "
Operational Check (Front)".
Does another symptom exist?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis to check for any codes. Refer to HAC-22, "
A/C Auto Amp. Self-Diagnosis".
Are any self-diagnosis codes present?
YES >> Refer to HAC-23, "A/C System Self-Diagnosis Code Chart".
NO >> GO TO 5.
5.CHECK AMBIENT SENSOR
Check and verify ambient s ensor circuit. Refer to HAC-78, "
Ambient Sensor Diagnosis Procedure".
Ambient temperature ° C (°F) Compressor ON intake temperature °C ( °F) Compressor OFF intake temperature °C ( °F)
0 (32) 5.5 (42) 5.0 (41)
10 (50) 5.5 (42) 5.0 (41)
20 (68) 5.5 (42) 5.0 (41)
30 (86) 4.0 (39) 3.5 (38)
40 (104) 3.5 (38) 3.0 (37)
50 (122) 3.5 (38) 3.0 (37)
Revision: March 2010 2008 QX56

HAC-88
< COMPONENT DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
POWER SUPPLY AND GROUND
CIRCUIT FOR CONTROLLER
POWER SUPPLY AND GROUND CIRCUIT FOR CONTROLLER
Component DescriptionINFOID:0000000001679824
COMPONENT DESCRIPTION
A/C auto amp.
The A/C auto amp. has a built-in microcomputer which processes
information sent from various sensors needed for air conditioner
operation. The air mix door motors, mode door motor, intake door
motor, defroster door motor, blower motor and compressor are then
controlled.
The A/C auto amp. is unitized with control mechanisms. When the
various switches and temperature dials are operated, data is input to
the A/C auto amp.
Self-diagnostic functions are also built into the A/C auto amp. to pro-
vide quick check of malfunctions in the auto air conditioner system.
Potentio Temperature Control (PTC)
There are two PTCs (driver and passenger) built into the A/C auto
amp. They can be set at an interval of 0.5° C (1.0°F) in the 18 °C
(60 °F) to 32° C (90°F) temperature range by rotating the temperature
dial. The set temperature is displayed.
A/C Auto Amp. Component Function CheckINFOID:0000000001679825
SYMPTOM: A/C system does not come on.
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERATIONAL CHECK - AUTO MODE
1. Press AUTO switch.
2. Display should indicate AUTO. Confirm that the compressor clutch engages (sound or visual inspection).
(Discharge air and blower speed will depend on am bient, in-vehicle and set temperatures.)
Can a symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.PERFORM COMPLETE OPERATIONAL CHECK
Perform a complete operational check and check for any symptoms. Refer to HAC-4, "
Operational Check
(Front)".
Can a symptom be duplicated?
YES >> Refer to HAC-3, "How to Perform Trouble Diagnosis For Quick And Accurate Repair".
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.CHECK POWER AND GROUND CIRCUIT
AWIIA0573ZZ
AWIIA0211GB
Revision: March 2010 2008 QX56

INSUFFICIENT COOLINGHAC-109
< SYMPTOM DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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INSUFFICIENT COOLING
Component Function CheckINFOID:0000000001679830
SYMPTOM: Insufficient cooling
INSPECTION FLOW
1.CONFIRM SYMPTOM BY PERFORMING OPERAT IONAL CHECK - TEMPERATURE DECREASE
1. Press the AUTO switch.
2. Turn temperature control dial (driver) counterclockwise until 18 °C (60° F) is displayed.
3. Check for cold air at discharge air outlets.
Can the symptom be duplicated?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK FOR ANY SYMPTOMS
Perform a complete operational check for any symptoms. Refer to HAC-4, "
Operational Check (Front)".
Does another symptom exist?
YES >> Refer to HAC-108, "SymptomMatrixChart".
NO >> System OK.
3.CHECK FOR SERVICE BULLETINS
Check for any service bulletins.
>> GO TO 4.
4.PERFORM SELF-DIAGNOSIS
Perform self-diagnosis Refer to HAC-22, "
A/C Auto Amp. Self-Diagnosis".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Refer to HAC-23, "
A/C System Self-Diagnosis Code Chart".
5.CHECK DRIVE BELTS
Check compressor belt tension. Refer to EM-13, "
Checking Drive Belts".
Is the inspection result normal?
OK >> GO TO 6.
NG >> Adjust or replace compressor belt. Refer to EM-13, "
Removal and Installation".
6.CHECK AIR MIX DOOR OPERATION
Check and verify air mix door mechanism for smooth operation. Refer to HAC-31, "
Air Mix Door Motor Compo-
nent Function Check".
Does air mix door operate correctly?
YES >> GO TO 7.
NO >> Check air mix door motor circuit. Refer to HAC-32, "
Air Mix Door Motor (Driver) Diagnosis Proce-
dure" or HAC-35, "Air Mix Door Motor (Passenger) Diagnosis Procedure".
7.CHECK COOLING FAN MOTOR OPERATION
Check and verify cooling fan moto r for smooth operation. Refer to EC-395, "
Component Inspection".
Does cooling fan motor operate correctly?
YES >> GO TO 8.
NO >> Check cooling fan motor. Refer to EC-395, "
Diagnosis Procedure".
8.CHECK WATER VALVE OPERATION
Check and verify water valve for smooth operation. Refer to HAC-76, "
Description".
Does water valve operate correctly?
YES >> GO TO 9.
Revision: March 2010 2008 QX56