2011 INFINITI QX56 sensor

HAC-1
VENTILATION, HEATER & AIR CONDITIONER
C
DE
F
G H
J
K L
M
SECTION HAC
A
B
HAC
N
O P
CONTENTS
HEATER & AIR CONDITIONING CONTROL SYSTEM
AUTOMATIC AIR CONDITIONING
PRECAUTION ................ ...............................
5
PRECAUTIONS .............................................. .....5
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
5
SYSTEM DESCRIPTION ..............................6
COMPONENT PARTS ................................... .....6
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ......
6
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Component Parts Location .............................
6
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Component Description ..................................
7
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ......
8
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM : Component Parts Location .............................
9
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM : Component Description ................................
10
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) ...................................................................... ....
10
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : Component Parts Location ..........................
11
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : Component Description ...............................
11
Aspirator ..................................................................12
Front Blower Motor ..................................................12
Rear Blower Motor ..................................................13
Refrigerant Pressure Sensor ...................................13
SYSTEM .............................................................14
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ....
14
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : System Diagram ...........................................
14
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : System Description .......................................
14
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Air Flow Control ............................................
15
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Air Inlet Control .............................................
16
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Air Outlet Control ..........................................
17
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Compressor Control ......................................
17
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Door Control ..................................................
18
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Temperature Control .....................................
21
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Fail-safe ........................................................
21
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ....
22
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM : System Diagram ...........................................
23
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM : System Description .......................................
23
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM : Air Flow Control ............................................
24
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM : Air Outlet Control ..........................................
25
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM : Door Control ..................................................
26
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM : Temperature Control .....................................
27
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) ....................................................................... ....
27
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : System Diagram ..........................................
28
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : System Description ......................................
28
Revision: 2010 May2011 QX56

HAC-2
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : Automatic Intake Control (Exhaust Gas /
Outside Odor Detecting Mechanism) .....................
28
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : Plasmacluster Control .................................
29
OPERATION ......................................................30
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ...
30
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Switch Name and Function ....................... ...
30
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ...
35
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM : Switch Name and Function ....................... ...
35
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) ....................................................................... ...
37
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : Switch Name and Function .........................
37
DIAGNOSIS SYSTEM (HVAC) ..........................39
Description ........................................................... ...39
CONSULT-III Function ...........................................39
ECU DIAGNOSIS INFORMATION ..............42
A/C AUTO AMP. ............................................. ...42
Reference Value .................................................. ...42
Fail-safe ..................................................................45
DTC Index ..............................................................45
ECM, IPDM E/R .................................................47
List of ECU Reference ......................................... ...47
WIRING DIAGRAM .....................................48
AUTOMATIC AIR CONDITIONING SYSTEM ...48
Wiring Diagram .................................................... ...48
BASIC INSPECTION ...................................60
DIAGNOSIS AND REPAIR WORK FLOW ..... ...60
Work Flow ............................................................ ...60
OPERATION INSPECTION ............................ ...62
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ...
62
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Work Procedure ........................................ ...
62
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ...
64
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM : Work Procedure ........................................ ...
64
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) ....................................................................... ...
66
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : Work Procedure ..........................................
66
SYSTEM SETTING ............................................68
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ...
68
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Temperature Setting Trimmer (Front) ..........
68
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Foot Position Setting Trimmer ......................
68
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Inlet Port Memory Function (FRE) ................
69
FRONT AUTOMATIC AIR CONDITIONING SYS-
TEM : Inlet Port Memory Function (REC) ...............
69
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM ........................................................................ ...
69
REAR AUTOMATIC AIR CONDITIONING SYS-
TEM : Temperature Setting Trimmer (Rear) ...........
69
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) ....................................................................... ...
70
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : Exhaust Gas / Outside Odor Detecting
Sensor Sensitivity Adjustment Function ..................
70
ACCS (ADVANCED CLIMATE CONTROL SYS-
TEM) : Auto Intake Switch Interlocking Movement
Change Function .....................................................
70
DTC/CIRCUIT DIAGNOSIS ........................72
U1000 CAN COMM CIRCUIT ......................... ...72
Description ........................................................... ...72
DTC Logic ...............................................................72
Diagnosis Procedure ...............................................72
U1010 CONTROL UNIT (CAN) .........................73
Description ........................................................... ...73
DTC Logic ...............................................................73
Diagnosis Procedure ...............................................73
B2578, B2579 FRONT IN-VEHICLE SENSOR ...74
DTC Logic ............................................................ ...74
Diagnosis Procedure ...............................................74
Component Inspection ............................................75
B257B, B257C AMBIENT SENSOR .................77
DTC Logic ............................................................ ...77
Diagnosis Procedure ...............................................77
Component Inspection ............................................78
B2581, B2582 INTAKE SENSOR .....................80
DTC Logic ............................................................ ...80
Diagnosis Procedure ...............................................80
Component Inspection ............................................81
B262A, B262B, B2657, B2658 EXHAUST
GAS/OUTSIDE ODOR DETECTING SENSOR
...
83
DTC Logic ............................................................ ...83
Diagnosis Procedure ...............................................83
Revision: 2010 May2011 QX56

HAC-3
C
DE
F
G H
J
K L
M A
B
HAC
N
O P
B2630, B2631 SUNLOAD SENSOR (DRIVER
SIDE) .............................................................. ....
86
DTC Logic ........................................................... ....86
Diagnosis Procedure ...............................................86
Component Inspection ............................................87
B2632, B2633 FRONT AIR MIX DOOR MO-
TOR (DRIVER SIDE) ..........................................
89
DTC Logic ........................................................... ....89
Diagnosis Procedure ...............................................89
B2634, B2635 FRONT AIR MIX DOOR MO-
TOR (PASSENGER SIDE) .................................
91
DTC Logic ........................................................... ....91
Diagnosis Procedure ...............................................91
B2636, B2637, B2638, B2639, B2654, B2655
FRONT MODE DOOR MOTOR ..........................
93
DTC Logic ........................................................... ....93
Diagnosis Procedure ...............................................93
B263D, B263E, B263F INTAKE DOOR MO-
TOR ....................................................................
95
DTC Logic ........................................................... ....95
Diagnosis Procedure ...............................................95
B2661, B2662, B2663 UPPER VENTILATOR
DOOR MOTOR ...................................................
97
DTC Logic ........................................................... ....97
Diagnosis Procedure ...............................................97
B2664, B2665 REAR AIR MIX DOOR MOTOR
....
99
DTC Logic ........................................................... ....99
Diagnosis Procedure ...............................................99
B2666, B2669, B266A REAR MODE DOOR
MOTOR .............................................................
101
DTC Logic ........................................................... ..101
Diagnosis Procedure .............................................101
B2667, B2668 SUNLOAD SENSOR (PAS-
SENGER SIDE) ................................................
103
DTC Logic ........................................................... ..103
Diagnosis Procedure .............................................103
Component Inspection ..........................................104
B266B, B266C REAR IN-VEHICLE SENSOR ..106
DTC Logic ........................................................... ..106
Diagnosis Procedure .............................................106
Component Inspection ..........................................107
B27B0 A/C AUTO AMP. ..................................109
DTC Logic ........................................................... ..109
Diagnosis Procedure .............................................109
POWER SUPPLY AND GROUND CIRCUIT ....110
A/C AUTO AMP. .................................................... ..110
A/C AUTO AMP. : Diagnosis Procedure ...............110
FRONT AIR MIX DOOR MOTOR (DRIVER SIDE) ..110
FRONT AIR MIX DOOR MOTOR (DRIVER SIDE)
: Diagnosis Procedure ......................................... ..
110
FRONT AIR MIX DOOR MOTOR (PASSENGER
SIDE) ...................................................................... ..
111
FRONT AIR MIX DOOR MOTOR (PASSENGER
SIDE) : Diagnosis Procedure .................................
111
FRONT MODE DOOR MOTOR ............................. ..112
FRONT MODE DOOR MOTOR : Diagnosis Pro-
cedure ....................................................................
112
INTAKE DOOR MOTOR ........................................ ..113
INTAKE DOOR MOTOR : Diagnosis Procedure ...113
REAR AIR MIX DOOR MOTOR ............................. ..114
REAR AIR MIX DOOR MOTOR : Diagnosis Pro-
cedure .................................................................. ..
114
REAR A/C CONTROL ........................................... ..115
REAR A/C CONTROL : Diagnosis Procedure .......115
REAR MODE DOOR MOTOR ............................... ..116
REAR MODE DOOR MOTOR : Diagnosis Proce-
dure .......................................................................
116
UPPER VENTILATOR DOOR MOTOR ...................116
UPPER VENTILATOR DOOR MOTOR : Diagno-
sis Procedure ....................................................... ..
116
DOOR MOTOR ................................................118
Diagnosis Procedure .............................................118
DOOR MOTOR COMMUNICATION CIRCUIT .120
Diagnosis Procedure .............................................120
FRONT BLOWER MOTOR .............................121
Diagnosis Procedure .............................................121
Component Inspection (Front Blower Motor) .........122
Component Inspection (Blower Relay) ..................123
IONIZER ..........................................................124
Component Function Check ..................................124
Diagnosis Procedure .............................................124
MAGNET CLUTCH .........................................126
Component Function Check ..................................126
Diagnosis Procedure .............................................126
REAR A/C CONTROL COMMUNICATION
SIGNAL ...........................................................
127
Diagnosis Procedure .............................................127
REAR A/C SOLENOID VALVE .......................128
Diagnosis Procedure .............................................128
Component Inspection ...........................................129
REAR BLOWER MOTOR ...............................131
Diagnosis Procedure .............................................131
Component Inspection ...........................................132
SYMPTOM DIAGNOSIS ............................133
Revision: 2010 May2011 QX56

HAC-4
FRONT AUTOMATIC AIR CONDITIONING
SYSTEM .......................................................... .
133
Diagnosis Chart By Symptom .............................. ..133
REAR AUTOMATIC AIR CONDITIONING
SYSTEM .......................................................... .
135
Diagnosis Chart By Symptom .............................. ..135
ACCS (ADVANCE CLIMATE CONTROL
SYSTEM) .........................................................
137
Symptom Table ................................................... ..137
INSUFFICIENT COOLING ...............................138
FRONT AIR CONDITIONER .................................. ..138
FRONT AIR CONDITIONER : Description ............138
FRONT AIR CONDITIONER : Diagnosis Proce-
dure .......................................................................
138
REAR AIR CONDITIONER .................................... ..139
REAR AIR CONDITIONER : Description ...............139
REAR AIR CONDITIONER : Diagnosis Procedure
..
139
INSUFFICIENT HEATING .............................. .140
FRONT AIR CONDITIONER .................................. ..140
FRONT AIR CONDITIONER : Description ............140
FRONT AIR CONDITIONER : Diagnosis Proce-
dure .......................................................................
140
REAR AIR CONDITIONER .................................... ..140
REAR AIR CONDITIONER : Description ...............141
REAR AIR CONDITIONER : Diagnosis Procedure
..
141
COMPRESSOR DOSE DOT OPERATE ........ .142
Description ........................................................... ..142
Diagnosis Procedure .............................................142
REMOVAL AND INSTALLATION ..............144
FRONT A/C CONTROL .................................. .144
Removal and Installation ..................................... ..144
REAR A/C CONTROL .....................................145
Removal and Installation ..................................... ..145
A/C AUTO AMP. ..............................................146
Removal and Installation ..................................... ..146
AMBIENT SENSOR ..........................................147
Removal and Installation ...................................... .147
IN-VEHICLE SENSOR ......................................148
FRONT A/C UNIT ASSEMBLY ...............................148
FRONT A/C UNIT ASSEMBLY : Removal and In-
stallation ............................................................... .
148
REAR A/C UNIT ASSEMBLY .................................148
REAR A/C UNIT ASSEMBLY : Removal and In-
stallation ............................................................... .
148
SUNLOAD SENSOR ........................................149
Removal and Installation ...................................... .149
INTAKE SENSOR .............................................150
Exploded View ..................................................... .150
Removal and Installation .......................................150
EXHAUST GAS/OUTSIDE ODOR SENSOR ...151
Removal and Installation ...................................... .151
DOOR MOTOR .................................................152
Exploded View ..................................................... .152
MODE DOOR MOTOR ........................................... .153
MODE DOOR MOTOR : Removal and Installation .153
AIR MIX DOOR MOTOR ........................................ .153
AIR MIX DOOR MOTOR : Removal and Installa-
tion ....................................................................... .
153
INTAKE DOOR MOTOR ........................................ .153
INTAKE DOOR MOTOR : Removal and Installa-
tion ........................................................................
153
UPPER VENTILATOR DOOR MOTOR ..................154
UPPER VENTILATOR DOOR MOTOR : Removal
and Installation ..................................................... .
154
REAR MODE DOOR MOTOR ................................ .154
REAR MODE DOOR MOTOR : Removal and In-
stallation ................................................................
154
REAR AIR MIX DOOR MOTOR ............................. .154
REAR AIR MIX DOOR MOTOR : Removal and In-
stallation ................................................................
154
IONIZER ............................................................155
Exploded View ..................................................... .155
Removal and Installation .......................................155
Revision: 2010 May2011 QX56

PRECAUTIONSHAC-5
< PRECAUTION > [AUTOMATIC AIR CONDITIONING]
C
D
E
F
G H
J
K L
M A
B
HAC
N
O P
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006275847
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty 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 AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision that would result in air ba g inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
 Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the
ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
 When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minutes before performing any service.
Revision: 2010 May2011 QX56

HAC-6
< SYSTEM DESCRIPTION >[AUTOMATIC AIR CONDITIONING]
COMPONENT PARTS
SYSTEM DESCRIPTION
COMPONENT PARTS
FRONT AUTOMATIC AIR CONDITIONING SYSTEM
FRONT AUTOMATIC AIR CONDITIONING
SYSTEM : Component Parts Location
INFOID:0000000006275848
1. Preset switch 2. Engine coolant temperature sensor
Refer to EC-16, "
Component Parts
Location". 3. IPDM E/R
Refer to PCS-4, "
Component Parts
Location".
4. ECM Refer to EC-16, "
Component Parts
Location"
5. Refrigerant pressure sensor 6. Ambient sensor
7. Magnet clutch 8. AV control unit Refer to AV- 9 , "
Component Parts Lo-
cation". 9. Combination meter
Refer to MWI-6, "
METER SYSTEM :
Component Parts Location".
10. Sunload sensor 11. Front display 12. Upper ventilator door motor
JMIIA0812ZZ
Revision: 2010 May2011 QX56

COMPONENT PARTSHAC-7
< SYSTEM DESCRIPTION > [AUTOMATIC AIR CONDITIONING]
C
D
E
F
G H
J
K L
M A
B
HAC
N
O P
FRONT AUTOMATIC AIR CONDITIONING SYSTEM : Component Description
INFOID:0000000006275849
13. Aspirator 14. Front air mix door motor (Driver side) 15. Intake sensor
16. Front mode door motor 17. Front air mix door motor (Passenger
side)18. Intake door motor
19. Front blower motor 20. A/C auto amp. 21. Front in-vehicle sensor
A. Left side of heater & cooling unit as- sembly B. Right side of heater & cooling unit as-
sembly C. Back side of blower unit assembly
D. Cluster lid C is removed E. Ins trument lower panel LH is re-
moved
Component Description
Ambient sensor Ambient sensor measures ambient air temperature. The sensor uses a
thermistor which is sensitive to the change in temperature. The electrical
resistance of the thermistor decreases as temperature increases.
AV c o n t r o l u n i t AV control unit transmits front A/C control operation signal to A/C auto amp.
via CAN communication line.
A/C auto amp. A/C auto amp. controls front automatic air conditioning system by inputting
and calculating signals from each sensor and each switch. A/C auto amp.
has self-diagnosis function. Diagnosis of front automatic air conditioning
system can be performed quickly.
Blower unit Front blower motor Refer to
HAC-12
.
Intake door motor The LCU (Local Control Unit) is installed to intake door motor so as to per-
form the multiplex commu
nication control (LIN).
Refer to HAC-18, "
FRONT AUTOMATIC AIR CONDITIONING SYSTEM :
Door Control".
Combination meter Combination meter transmits vehicle speed signal to A/C auto amp. via
CAN communication line.
ECM ECM controls compressor according to status of engine and refrigerant.
ECM transmits engine coolant temperature signal to A/C auto amp. via
CAN communication line.
Engine coolant temperature sensor Engine coolant temperature sensor measures engine coolant temperature.
The sensor uses a thermistor which is sensitive to the change in tempera-
ture. The electrical resistance of the thermistor decreases as temperature
increases.
Front display Front display indicates operation status of front automatic air conditioning
system.
Front in-vehicle sensor Front in-vehicle sensor measures temperature of intake air that flows
through aspirator to passenger room. The sensor uses a thermistor which
is sensitive to the change in temperature. The electrical resistance of the
thermistor decreases as temperature increases.
Revision: 2010 May2011 QX56

HAC-8
< SYSTEM DESCRIPTION >[AUTOMATIC AIR CONDITIONING]
COMPONENT PARTS
REAR AUTOMATIC AIR CONDITIONING SYSTEM
Heater & cooling unit
assemblyAspirator Refer to
HAC-12
.
Front air mix door motor (Driver
side) The LCU (Local Control Unit) is installe
d to front air mix door motor (driver
side) so as to perform the multiplex communication control (LIN).
Refer to HAC-18, "
FRONT AUTOMATIC AIR CONDITIONING SYSTEM :
Door Control".
Front air mix door motor (Pas-
senger side) The LCU (Local Control Unit) is installed to front air mix door motor (pas-
senger side) so as to perform the multiplex communication control (LIN).
Refer to
HAC-18, "
FRONT AUTOMATIC AIR CONDITIONING SYSTEM :
Door Control".
Front mode door motor The LCU (Local Control Unit) is installed to front mode door motor so as to
perform the multiplex communication control (LIN).
Refer to
HAC-18, "
FRONT AUTOMATIC AIR CONDITIONING SYSTEM :
Door Control".
Intake sensor Intake sensor measures temperature of front evaporator fin temperature.
The sensor uses a thermistor which is sensitive to the change in tempera-
ture. The electrical resistance of the thermistor decreases as temperature
increases.
Upper ventilator door motor The LCU (Local Control Unit) is installed to upper ventilator door motor so
as to perform the multiplex communication control (LIN).
Refer to
HAC-18, "
FRONT AUTOMATIC AIR CONDITIONING SYSTEM :
Door Control".
IPDM E/R A/C relay is integrated in
IPDM E/R. IPDM E/R op erates A/C relay when A/
C compressor request signal is received from ECM via CAN communica-
tion line.
Magnet clutch The magnet clutch is the device that drives the compressor with the signal
from IPDM E/R. Compressor is driven by the magnet clutch which is mag-
netized by electric power supply. IPDM controls magnet clutch by turning
the built in A/C relay to ON
⇔ OFF according to ECM request.
Preset switch Preset switch is integrated with front A/C control and AV operation switch.
Front A/C control operation signal is transmitted from preset switch to AV
control unit via communication line.
Refrigerant pressure sensor Refer to HAC-13
.
Sunload sensor Sunload sensor measures sunload amount. This sensor is a dual system
so that sunload for driver side and passenger side are measured separate-
ly. This sensor converts sunload amount to voltage signal by photodiode
and transmits to A/C auto amp..
Component Description
Revision: 2010 May2011 QX56