2009 INFINITI QX56 sensor

HAC-2
MAGNET CLUTCH ............................................72
System Description .............................................. ...72
Magnet Clutch Component Function Check ........ ...72
Magnet Clutch Diagnosis Procedure ................... ...73
WATER VALVE CIRCUIT ..................................77
Description ........................................................... ...77
Water Valve Diagnosis Procedure ..........................77
AMBIENT SENSOR ...........................................79
Component Description ....................................... ...79
Ambient Sensor Diagnosis Procedure ....................79
Ambient Sensor Component Inspection .................80
IN-VEHICLE SENSOR .......................................82
Component Description ....................................... ...82
In-Vehicle Sensor Diagnosis Procedure .................82
In-Vehicle Sensor Component Inspection ..............84
OPTICAL SENSOR ...........................................85
Component Description ..........................................85
Optical Sensor Diagnosis Procedure ......................85
INTAKE SENSOR ..............................................87
System Description .............................................. ...87
Intake Sensor Diagnosis Procedure .......................87
Intake Sensor Component Inspection ................. ...88
POWER SUPPLY AND GROUND CIRCUIT
FOR CONTROLLER ..........................................
89
Component Description ....................................... ...89
A/C Auto Amp. Component Function Check ..........89
A/C Auto Amp Power and Ground Diagnosis Pro-
cedure .....................................................................
90
ECU DIAGNOSIS .......................................91
AIR CONDITIONER CONTROL ..................... ...91
A/C Auto Amp. Terminals Reference Values ..........91
Wiring Diagram .................................................... ...93
SYMPTOM DIAGNOSIS ...........................109
AIR CONDITIONER CONTROL ..................... ..109
Symptom Matrix Chart ........................................ .109
INSUFFICIENT COOLING ................................110
Component Function Check ................................ .110
Diagnostic Work Flow ...........................................111
Performance Chart ................................................113
Trouble Diagnoses for Abnormal Pressure ...........114
INSUFFICIENT HEATING ................................118
Component Function Check .................................118
NOISE ...............................................................120
Component Function Check ................................ .120
MEMORY FUNCTION DOES NOT OPERATE ..122
Memory Function Check ...................................... .122
PRECAUTION ...........................................123
PRECAUTIONS .............................................. ..123
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" .............................................................. .
123
Working with HFC-134a (R-134a) ........................ .123
Precaution for Service Equipment ........................124
Revision: December 20092009 QX56

FUNCTION INFORMATIONHAC-7
< FUNCTION DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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FUNCTION DIAGNOSIS
FUNCTION INFORMATION
Component Part LocationINFOID:0000000003775327
ENGINE COMPARTMENT
AWIIA1132GB
1. Water valve F68 2. Refrigerant pressure sensor E48 3. Ambient sensor E1
4. A/C compressor F3
Revision: December 20092009 QX56

HAC-8
< FUNCTION DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
FUNCTION INFORMATION
PASSENGER COMPARTMENT
1. A/C auto amp. M49, M50
2. In-vehicle sensor M323. Intake sensor M146
4. Intake door motor M58 5. Variable blower control (front)
M122 6. Air mix door motor (passenger) M143
7. Mode door motor (front) M142 8. Defroster door motor M144 9. Air mix door motor (driver) M147
10. Optical sensor M302 ⇐:Front
AWIIA0567ZZ
Revision: December 20092009 QX56

REFRIGERATION SYSTEMHAC-11
< FUNCTION DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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REFRIGERATION SYSTEM
Refrigerant CycleINFOID:0000000004040375
REFRIGERANT FLOW
The refrigerant flows in the standard pattern, that is, through the compressor, the condenser with liquid tank,
through the front and rear evaporators, and back to the compressor. The refrigerant evaporation through the
evaporator coils are controlled by front and rear externally equalized expansion valves, located inside the front
and rear evaporator cases.
Refrigerant System ProtectionINFOID:0000000004040376
REFRIGERANT PRESSURE SENSOR
The refrigerant system is protected against excessively hi gh or low pressures by the refrigerant pressure sen-
sor, located on the condenser. If the system pressure rises above or falls below the specifications, the refriger-
ant pressure sensor detects the pressure inside the refrigerant line and sends a voltage signal to the ECM.
The ECM de-energizes the A/C relay to disengage the magnetic compressor clutch when pressure on the high
pressure side detected by refrigerant pressu re sensor is over about 2,746 kPa (28 kg/cm
2, 398 psi), or below
about 120 kPa (1.22 kg/cm
2, 17.4 psi).
PRESSURE RELIEF VALVE
The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor.
When the pressure of refrigerant in the system incr eases to an abnormal level [more than 2,990 kPa (30.5 kg/
Revision: December 20092009 QX56

AUTOMATIC AIR CONDITIONER SYSTEMHAC-13
< FUNCTION DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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AUTOMATIC AIR CONDITIONER SYSTEM
Control System DiagramINFOID:0000000003775331
CONTROL SYSTEM
The control system consists of input sensors, switches, the A/C auto amp.(microcomputer) and outputs.
The relationship of these components is shown in the figure below:
Control System DescriptionINFOID:0000000003775332
CONTROL OPERATION
AWIIA0088GB
Revision: December 20092009 QX56

AUTOMATIC AIR CONDITIONER SYSTEMHAC-15
< FUNCTION DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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Rear Air Controls
REAR TEMPERATURE CONTROL DIAL (FRONT/REAR)
The temperature increases or dec reases the set temperature.
REAR MODE SWITCHES (FRONT/REAR)
Controls the air discharge outlets.
REAR BLOWER CONTROL DIAL (FRONT)
When the REAR CTRL switch is in the off (indicator off) the rear air control (front) controls the rear blower
motor speed regardless of the rear air control (rear) blow er control dial (rear) position. The rear air control
(front) controls the blower motor speed.
REAR BLOWER CONTROL DIAL (REAR)
When the REAR CTRL switch is in the on (indicator on) the rear air control (rear) controls the rear blower
motor speed regardless of the rear air control (front) blow er control dial (front) position. The rear air control
(rear) controls the blower motor speed.
MAGNET CLUTCH CONTROL
When A/C switch or DEF switch is pressed, A/ C auto amp. inputs compressor ON signal to BCM.
BCM sends compressor ON signal to ECM and A/C auto amp., via CAN communication line.
ECM judges whether compressor can be turned ON, based on each sensor status (refrigerant pressure sen-
sor signal, throttle angle sensor, etc.). If it judges compressor can be turned ON, it sends compressor ON sig-
nal to IPDM E/R, via CAN communication line.
AWIIA0082ZZ
1. Rear air control (front )2. Rear air control (rear)
AWIIA1069GB
Revision: December 20092009 QX56

HAC-20
< FUNCTION DIAGNOSIS >[AUTOMATIC AIR CONDITIONER]
DIAGNOSIS SYSTEM (HVAC)
DIAGNOSIS SYSTEM (HVAC)
CONSULT-III Function (HVAC)INFOID:0000000003775338
CONSULT-III can display each diagnostic item using the diagnostic test modes shown following.
SELF-DIAGNOSIS
Display Item List
DATA MONITOR
Display Item List
Diagnostic mode
Description
SELF-DIAG RESULTS Displays A/C au to amp. self-diagnosis results.
DATA MONITOR Displays A/C auto amp. input/output data in real time.
CAN DIAG SUPPORT MNTR The result of transmit/receive diagnosis of CAN communication can be read. ECU PART NUMBER A/C auto amp. part number can be read.
DTC Description
Reference page
B2573 Battery voltage out of range CHG-8, "
Inspection Procedure"
B2578 In-vehicle sensor circuit out of range (low)
HAC-82, "In-Vehicle Sensor Diagnosis Procedure"B2579 In-vehicle sensor circuit out of range (high)
B257B Ambient sensor circuit short HAC-79, "
Ambient Sensor Diagnosis Procedure"B257C Ambient sensor circuit open
B257F Optical sensor (Driver) circuit open or short HAC-85, "
Optical Sensor Diagnosis Procedure".
B2580 Optical sensor (Passenger) circuit open or short
B2581 Intake sensor circuit short HAC-87, "
Intake Sensor Diagnosis Procedure"B2582 Intake sensor circuit open
U1000 CAN bus fault LAN-14, "
Trouble Diagnosis Flow Chart"
Monitor itemValue Contents
BATT VIA CAN "V" Displays battery voltage signal.
IGN VIA CAN "ON/OFF" Displays ignition switch signal.
DVR SUNLD SEN "w/m2" Displays optical sensor (driver) signal.
PAS SUNLD SEN "w/m2" Displays optical sensor (passenger) signal.
AMB TEMP SEN "° C" Displays ambient sensor signal.
EVAP TEMP SEN "° C" Displays intake sensor signal.
INCAR TMP SEN "° C" Displays in-vehicle sensor signal.
RR TEMPSET FR "V" Displays air mix door (front) set point signal.
RR TEMPSET RR "V" Displays air mix door (rear) set point signal.
MODE FDBCK "V" Displays mode door motor feedback signal.
DVR MIX FDBCK "V" Displays air mix door motor (driver) feedback signal.
PAS MIX FDBCK "V" Displays air mix door motor (passenger) feedback signal.
RR FDBCK "V" Displays air mix door motor (rear) feedback signal.
DEF FDBCK "V" Displays defroster door motor feedback signal.
Revision: December 20092009 QX56

SELF-DIAGNOSIS FUNCTIONHAC-23
< FUNCTION DIAGNOSIS > [AUTOMATIC AIR CONDITIONER]
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SELF-DIAGNOSIS FUNCTION
A/C Auto Amp. Self-DiagnosisINFOID:0000000003775340
A/C SYSTEM SELF-DI AGNOSIS FUNCTION
The self-diagnosis function is built into the A/C auto amp. to quickly locate the cause of malfunctions.
DESCRIPTION
The self-diagnostic system diagnoses sensors, CAN system, and battery voltage on A/C auto amp. Refer to
applicable sections (items) for details. Fault codes (if any are present) will be displayed in the ambient temper-
ature display area. Refer to HAC-24, "
A/C System Self-Diagnosis Code Chart".
SELF-DIAGNOSTIC MODE
NOTE:
Radio must be off.
1. On the A/C and AV switch assembly, press the "SETTING" but- ton and twist the volume knob clockwise and counterclockwise
until the Self-Diagnosis screen shows on the display.
2. Scroll down to "Confirmation/Adjustment" and press the "ENTER" button.
3. Scroll down to "Climate Control" and press the "ENTER" button.
4. The fan bars will flash on the display during the self-test, and then the fault codes will display in the ambient temperature area.
They will continue scrolling until diagnostic mode is exited.
5. Exit by pressing the "BACK" button on A/C and AV switch assembly until display returns to its normal operation screen.
HVAC system will be OFF.
The self-diagnostic system diagnoses sensors, CAN system, and battery voltage on A/C auto amp. Refer to
applicable sections (items) for details. Fault codes (if any are present) will be displayed in the ambient temper-
ature display area. Refer to HAC-24, "
A/C System Self-Diagnosis Code Chart".
A/C and AV Switch A ssembly Self-DiagnosisINFOID:0000000003775341
A/C and AV switch assembly self-diagnosis function
The ON/OFF operation (continuity) of each switch in the A/C and AV switch assembly can be checked.
Self-diagnosis mode
AWNIA0098ZZ
AWIIA0081ZZ
Revision: December 20092009 QX56