air conditioner INFINITI FX35 2008 Service Manual

ABCDEFGHIJKLQUICK REFERENCE INDEX AGENERAL INFORMATIONGIGeneral InformationBENGINEEMEngine MechanicalLUEngine Lubrication SystemCOEngine Cooling SystemECEngine Control SystemFLFuel SystemEXExhaust SystemACCAccelerator Control SystemCTRANSMISSION/
TRANSAXLEATAutomatic TransmissionDDRIVELINE/AXLETFTransferPRPropeller ShaftFFDFront Final DriveRFDRear Final DriveFAXFront AxleRAXRear AxleESUSPENSIONFSUFront SuspensionRSURear SuspensionWTRoad Wheels & TiresFBRAKESBRBrake SystemPBParking Brake SystemBRCBrake Control SystemGSTEERINGPSPower Steering SystemHRESTRAINTSSBSeat BeltsSRSSupplemental Restraint System
(SRS)IBODYBLBody, Lock & Security SystemGWGlasses, Window System & Mir-
rorsRFRoofEIExterior & InteriorIPInstrument PanelSESeatJAIR CONDITIONERATCAutomatic Air ConditionerKELECTRICALSCStarting & Charging SystemLTLighting SystemDIDriver Information SystemWWWiper, Washer & HornBCSBody Control SystemLANLAN SystemAVAudio Visual, Navigation & Tele-
phone SystemACSAuto Cruise Control SystemPGPower Supply, Ground & Circuit Ele-
mentsLMAINTENANCEMAMaintenanceEdition: April 2007
Revision: April 2007

ATC-1
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CONTENTS
AUTOMATIC AIR CONDITIONER
SERVICE INFORMATION .. ..........................3
PRECAUTIONS .............................................. .....3
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ......
3
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect .....................................
3
Precaution for Procedure without Cowl Top Cover ......4
Precaution for Working with HFC-134a (R-134a) ......4
General Refrigerant Precaution ................................4
Precaution for Refrigerant Connection ......................5
Precaution for Service of Compressor ......................9
Precaution for Service Equipment .............................9
Precaution for Leak Detection Dye .........................11
PREPARATION ..................................................13
Special Service Tool ........................................... ....13
HFC-134a (R-134a) Service Tool and Equipment ....13
Commercial Service Tool ........................................16
REFRIGERATION SYSTEM ..............................17
Refrigerant Cycle ................................................ ....17
Refrigerant System Protection ................................17
V-6 Variable Displacement Compressor .................17
Component Part Location .......................................21
LUBRICANT ................................................... ....22
Maintenance of Lubricant Quantity in Compressor ....22
AIR CONDITIONER CONTROL .........................24
Description of Air Conditioner LAN Control Sys-
tem ...................................................................... ....
24
System Construction ...............................................24
Description of Control System .................................27
Control Operation ....................................................27
Fail-Safe Function ...................................................28
Discharge Air Flow ..................................................29
System Description .................................................30
CAN Communication System Description ...............30
TROUBLE DIAGNOSIS .....................................32
CONSULT-III Function ........................................ ....32
How to Perform Trouble Diagnosis for Quick and
Accurate Repair .......................................................
32
Component Parts and Harness Connector Loca-
tion ...........................................................................
34
Schematic ................................................................36
Wiring Diagram - A/C - ............................................37
Auto Amp. Terminal and Reference Value ..............42
Self-Diagnosis Function ...........................................43
Operational Check ...................................................50
Power Supply and Ground Circuit for Auto Amp .....52
LAN System Circuit .................................................54
Mode Door Motor Circuit .........................................57
Air Mix Door Motor Circuit .......................................59
Air Mix Door Motor PBR Circuit ...............................62
Intake Door Motor Circuit .........................................62
Blower Motor Circuit ................................................64
Magnet Clutch Circuit ..............................................69
Insufficient Cooling ..................................................75
Insufficient Heating ..................................................82
Noise .......................................................................83
Self-Diagnosis .........................................................84
Memory Function .....................................................85
Ambient Sensor Circuit ............................................86
In-vehicle Sensor Circuit ..........................................88
Sunload Sensor Circuit ............................................91
Intake Sensor Circuit ...............................................94
CONTROLLER ..................................................97
Removal and Installation of A/C and AV Switch ......97
AUTO AMP ........................................................98
Removal and Installation of Unified Meter and A/C
Amp .........................................................................
98
AMBIENT SENSOR ..........................................99
Removal and Installation .........................................99
IN-VEHICLE SENSOR ....................................100
Removal and Installation .......................................100
SUNLOAD SENSOR .......................................101
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ATC-4
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PRECAUTIONS
Precaution for Procedure without Cowl Top Cover
INFOID:0000000001612932
When performing the procedure after removing cowl top cover, cover
the lower end of windshield with urethane, etc.
Precaution for Working with HFC-134a (R-134a)INFOID:0000000001328153
CAUTION:
 CFC-12 (R-12) refrigerant and HFC-134a (R-134a) refr igerant are not compatible. If the refrigerants
are mixed and compressor malfunct ion is likely to occur, refer to “CONTAMINATED REFRIGERANT”
below. To determine the purity of HFC-134a (R-134a) in the vehicle and recovery tank, use Refriger-
ant Recovery/Recycling Rech arging equipment and Refrigerant Identifier.
 Use only specified lubricant for the HFC-134a (R-134a) A/C system and HFC-134a (R-134a) compo-
nents. If lubricant other than that specified is used, compressor malfunction is likely to occur.
 The specified HFC-134a (R-134a) lu bricant rapidly absorbs moisture from the atmosphere. The fol-
lowing handling precauti ons must be observed:
- When removing refrigerant components from a vehicle, immediately cap (seal) the component to
minimize the entry of moisture from the atmosphere.
- When installing refrigerant components to a vehic le, never remove the caps (unseal) until just before
connecting the components. Connect all refriger ant loop components as quickly as possible to min-
imize the entry of moisture into system.
- Only use the specified lubricant fr om a sealed container. Immediately reseal containers of lubricant.
Without proper sealing, lubrican t will become moisture saturated and should not be used.
- Never allow lubricant (Nissan A/C System Oil Type S) to come in contact with styrene foam parts.
Damage may result.
CONTAMINATED REFRIGERANT
If a refrigerant other than pure HFC-134a (R-134a) is identified in a vehicle, take appropriate steps
shown below:
 Explain to the customer that environmental regulations prohibit the release of contaminated refrigerant into
the atmosphere.
 Explain that recovery of the contaminated refri gerant could damage service equipment and refrigerant sup-
ply.
 Suggest the customer return the vehicle to the locati on of previous service where the contamination may
have occurred.
 In case of repairing, recover the refrigerant using only dedicated equipment and containers. Never
recover contaminated refrigerant into the existing service equipment. If the facility does not have ded-
icated recovery equipment, contact a local refrigerant pr oduct retailer for available service. This refrigerant
must be disposed of in accordance with all federal and local regulations. In addition, replacement of all
refrigerant system components on the vehicle is recommended.
 If the vehicle is within the warranty period, the air conditioner warranty is void. Please contact Nissan Cus-
tomer Affairs for further assistance.
General Refrigerant PrecautionINFOID:0000000001328154
WARNING:
 Avoid breathing A/C refrigerant and lubricant vap or or mist. Exposure may irritate eyes, nose and
throat. Remove HFC-134a (R-134a) from the A/C syst em, using certified service equipment meeting
requirements of SAE J-2210 [HFC-134a (R-134a) recycling equipment], or J-2209 [HFC-134a (R-134a)
recovery equipment]. If accidental system discharge occurs, ventilate work area before resuming
service. Additional health and saf ety information may be obtained from refrigerant and lubricant
manufacturers.
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PRECAUTIONSATC-9
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CAUTION:
When replacing or cleaning refrigerant cycle components, observe the following.
 When the compressor is removed, store it in the sam e way at it is when mounted on the car. Failure
to do so will cause lubricant to enter the low-pressure chamber.
 When connecting tubes, always use a to rque wrench and a back-up wrench.
 After disconnecting tubes, immediately plug all op enings to prevent entry of dust and moisture.
 When installing an air conditioner in the vehicle, connect the pipes at the final stage of the operation.
Never remove the seal caps of pipes and other compon ents until just before required for connection.
 Allow components stored in cool areas to warm to working area temperature before removing seal
caps. This prevents condensation from forming inside A/C components.
 Thoroughly remove moisture from the refriger ation system before charging the refrigerant.
 Always replace used O-rings.
 When connecting tubes, apply lubricant to circle of the O-rings shown in illustration. Be careful not
to apply lubricant to threaded portion.
 O-ring must be closely att ached to the groove of tube.
 When replacing the O-ring, be careful not to damage O-ring and tube.
 Connect tube until a click can be heard, then tighten the nut or bolt by hand. Make sure that the O-
ring is installed to tube correctly.
 After connecting line, perform leak test and make sure that there is no leakage from connections.
When the refrigerant leaking point is found, disconnect that line and replace the O-ring. Then tighten
connections of seal seat to the specified torque.
Precaution for Service of CompressorINFOID:0000000001328156
 Plug all openings to prevent moisture and foreign matter from entering.
 When the compressor is removed, store it in th e same way at it is when mounted on the car.
 When replacing or repairing compressor, follow “Maintenance of Lubricant Quantity in Compressor”
exactly. Refer to ATC-22, "
Maintenance of Lubricant Quantity in Compressor".
 Keep friction surfaces between clut ch and pulley clean. If the surface is contaminated with lubricant,
wipe it off by using a clean w aste cloth moistened with thinner.
 After compressor service operation, turn the compr essor shaft by hand more than five turns in both
directions. This will equally dist ribute lubricant inside the compressor. After the compressor is
installed, let the engine idle and operate the compressor for one hour.
 After replacing the compressor magnet clutch, ap ply voltage to the new one and check for normal
operation.
Precaution for Service EquipmentINFOID:0000000001328157
RECOVERY/RECYCLING EQUIPMENT
Name : Nissan A/C System Oil Type S
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ATC-24
< SERVICE INFORMATION >
AIR CONDITIONER CONTROL
AIR CONDITIONER CONTROL
Description of Air Conditioner LAN Control SystemINFOID:0000000001328167
The LAN (Local Area Network) syst em consists of unified meter and A/C amp., mode door motor, air mix door
motors and intake door motor.
A configuration of these component s is shown in the figure below.
System ConstructionINFOID:0000000001328168
A small network is constructed between the unifi ed meter and A/C amp., air mix door motors, mode door
motor and intake door motor. The unified meter and A/C amp. and motors are connected by data transmission
lines and motor power supply lines. The LAN network is built through the ground circuits of each door motor.
Addresses, motor opening angle signals, motor stop si gnals and error checking messages are all transmitted
through the data transmission lines connecting the unified meter and A/C amp. and each door motor.
The following functions are contained in LCUs built into the air mix door motors, the mode door motor and the
intake door motor.
 Address
 Motor opening angle signals
 Data transmission
 Motor stop and drive decision
 Opening angle sensor (PBR function)
 Comparison
 Decision (Unified meter and A/C amp. indicated value and motor opening angle comparison)
OPERATION
The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp.
sends mode door, air mix door and intake door opening angle data to the mode door motor LCU, air mix door
motor LCU and intake door motor LCU.
The mode door motor, air mix door motors and intake door motor read their respective signals according to the
address signal. Opening angle indication signals received from the unified meter and A/C amp. and each of
the motor position sensors is compared by the LCUs in each door motor with the existing decision and open-
ing angles. Subsequently, HOT/COLD, DEF/VENT and FRE/ REC operation is selected. The new selection
data is returned to the unified meter and A/C amp.
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AIR CONDITIONER CONTROLATC-25
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TRANSMISSION DATA AND TRANSMISSION ORDER
Unified meter and A/C amp. data is transmitted consecut ively to each of the door motors following the form
shown in figure below.
Sta rt:
Initial compulsory signal is sent to each of the door motors.
Address:
Data sent from the unified meter and A/C amp. are selected according to data-based decisions made by the
air mix door motor, mode door motor and intake door motor.
If the addresses are identical, the opening angle data and error check signals are received by the door motor
LCUs. The LCUs then make the appropriate error decis ion. If the opening angle data have no error, door con-
trol begins.
If an error exists, the received data are rejected and corrected data received. Finally, door control is based
upon the corrected opening angle data.
Opening Angle:
Data that shows the indicated door opening angle of each door motor.
Error Check:
In this procedure, transmitted and received data is check ed for errors. Error data are then compiled. The error
check prevents corrupted data from being used by the ai r mix door motor, the mode door motor and the intake
door motor. Error data can be related to the following symptoms.
 Malfunction of electrical frequency
 Poor electrical connections
 Signal leakage from transmission lines
 Signal level fluctuation
Stop Signal:
At the end of each transmission, a stop operation, in-oper ation, or internal malfunction message is delivered to
the unified meter and A/C amp. This comple tes one data transmission and control cycle.
AIR MIX DOOR CONTROL (AUTOMATIC TEMPERATURE CONTROL)
RJIA1748E
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ATC-26
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AIR CONDITIONER CONTROL
The air mix doors are automatically controlled so that in-vehicle temperature is maintained at a predetermined
value by the temperature setting, ambient temper ature, in-vehicle temperature and amount of sunload.
FAN SPEED CONTROL
Blower speed is automatically controlled by the temperature setting, ambient temperature, in-vehicle tempera-
ture, intake temperature, amount of sunload and air mix door position.
With pressing AUTO switch, the blower motor starts to gradually increase air flow volume.
When engine coolant temperature is low, the blower moto r operation is delayed to prevent cool air from flow-
ing.
INTAKE DOOR CONTROL
The intake doors are automatically controlled by the tem perature setting, ambient temperature, in-vehicle tem-
perature, intake temperature, amount of s unload and ON/OFF operation of the compressor.
MODE DOOR CONTROL
The mode door is automatically controlled by the temperat ure setting, ambient temperature, in-vehicle temper-
ature, intake temperature and amount of sunload.
MAGNET CLUTCH CONTROL
When A/C switch, AUTO switch or DEF switch is pr essed, unified meter and A/C amp. transmits compressor
ON signal to BCM.
BCM sends compressor ON signal to ECM, via CAN communication.
ECM judges whether compressor can be turned ON, based on each sensor status (refrigerant-pressure sen-
sor signal, throttle angle, etc.). If it judges compre ssor can be turned ON, it sends compressor ON signal to
IPDM E/R, via CAN communication.
Upon receipt of compressor ON signal from ECM, IPDM E/R turns air conditioner relay ON to operate com-
pressor.
When sending compressor ON signal to IPDM E/R via CAN communication, ECM simultaneously sends com-
pressor feedback signal to unified meter and A/C amp. via CAN communication.
Unified meter and A/C amp., then, uses input compressor feedback signal to control air inlet.
SELF-DIAGNOSIS SYSTEM
The self-diagnosis system is built into the unified mete r and A/C amp. to quickly locate the cause of malfunc-
tions.
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AIR CONDITIONER CONTROLATC-27
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Description of Control SystemINFOID:0000000001328169
The control system consists of input sensors, swit ches, the unified meter and A/C amp. (microcomputer) and
outputs. The relationship of these co mponents is shown in the figure below:
Control OperationINFOID:0000000001328170
DISPLAY SCREEN
The operation status of the system is displayed on the screen.
AUTO SWITCH
 The compressor, intake doors, air mix doors, mode doors and blower speed are automatically controlled so
that the in-vehicle temperature will reach, and be mainta ined at the set temperature selected by the operator.
SJIA1658E
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ATC-28
< SERVICE INFORMATION >
AIR CONDITIONER CONTROL
 When pressing AUTO switch, air inlet, air outlet, fan speed, and discharge air temperature are automatically
controlled.
TEMPERATURE CONTROL SWITCH (POTENTIO TEMPERATURE CONTROL) (DRIVER SIDE)
The set temperature is increased or decreased with this switch.
TEMPERATURE CONTROL SWITCH (POTENTIO TEMPERATURE CONTROL) (PASSENGER
SIDE)
 The set temperature is increased or decreased with this switch.
 When the temperature switch is pressed, the DUA L switch indicator will automatically illuminate.
INTAKE SWITCH
 When intake switch is ON, REC LED turns ON, and air inlet is fixed to REC.
 When press intake switch again, FRE LED turns ON, and air inlet is fixed to FRE.
 When intake switch is pressed for approximately 1. 5 seconds or longer, FRE and REC LEDs blink twice.
Then, automatic control mode is entered. Inlet status is displayed by LED even during automatic controlled.
 When FRE LED is turned ON, shifting mode position to D/ F or DEF, or when compressor is turned from ON
to OFF, intake switch is automatically turned OFF (fixed to FRE mode). REC mode can be re-entered by
pressing intake switch again, and then compressor is turned ON. (Except D/F or DEF position)
DEFROSTER (DEF) SWITCH
Mode doors are set to the defrost position with this switch . Also, intake doors are set to the outside air position,
and compressor turns ON.
REAR WINDOW DEFOGGER SWITCH
When illumination is ON, rear window is defogged.
OFF SWITCH
Compressor and blower are OFF, the intake door s and the mode doors are automatically controlled.
A/C SWITCH
Compressor is ON or OFF with this switch.
(Pressing the A/C switch when the A/C switch is ON will turn OFF the A/C switch and compressor.)
MODE SWITCH
The air discharge outlets is controlled with this switch.
FAN SWITCH
The blower speed is manually controlled with this swit ch. Seven speeds are available for manual control (as
shown on the display screen).
DUAL SWITCH
 When the DUAL switch indicator is illuminated, the driver side and passenger side temperature can each be set independently.
 When the DUAL switch indicator is not illuminated, t he driver side setting temperature is applied to both
sides.
Fail-Safe FunctionINFOID:0000000001328171
If a communication error exists between the unified meter and A/C amp., and the A/C and AV switch for 30
seconds or longer, air conditioner is controlled under following conditions:
Compressor : ON
Air outlet : AUTO
Air inlet : FRE (Fresh)
Blower fan speed : AUTO
Set temperature : Setting befo re communication error occurs
Display : OFF
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AIR CONDITIONER CONTROLATC-29
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Discharge Air FlowINFOID:0000000001328172
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