2004 INFINITI FX35 control

ATC-8
PRECAUTIONS
Revision: 2004 November 2004 FX35/FX45
Precautions for Refrigerant ConnectionAJS0013Y
A new type refrigerant connection has been introduced to all refrigerant lines except the following location.

Expansion valve to evaporator

Refrigerant pressure sensor to condenser
ABOUT ONE-TOUCH JOINT
Description

One-touch joints are pipe joints which do not require tools during piping connection.

Unlike conventional connection methods using union nuts and flanges, controlling tightening torque at
connection point is not necessary.

When removing a pipe joint, use a disconnector.
COMPONENT PARTS
FUNCTIONS OF COMPONENT PARTS
NOTE:

Garter spring cannot be removed from cage of male-side piping.

Indicator ring remains near piping connection point, however, this is not a malfunction. (This is to check
piping connection during factory assembly.)
Pipe (Male side)
Retains O-rings.

Retains garter spring in cage.
Garter spring Anchors female side piping.
Indicator ringWhen connection is made properly, this is ejected from male-side piping. (This part is no longer neces-
sary after connection.)
O-ring Seals connection point. (Not reusable)
Pipe (Female side)

Seals connection by compressing O-rings.

Anchors piping connection using flare and garter spring.
RJIA0970E

PRECAUTIONS
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Revision: 2004 November 2004 FX35/FX45
SERVICE COUPLERS
Never attempt to connect HFC-134a (R-134a) service couplers to a
CFC-12 (R-12) A/C system. The HFC-134a (R-134a) couplers will
not properly connect to the CFC-12 (R-12) system. However, if an
improper connection is attempted, discharging and contamination
may occur.
REFRIGERANT WEIGHT SCALE
Verify that no refrigerant other than HFC-134a (R-134a) and speci-
fied lubricants have been used with the scale. If the scale controls
refrigerant flow electronically, the hose fitting must be 1/2
″ -16
ACME.
CHARGING CYLINDER
Using a charging cylinder is not recommended. Refrigerant may be vented into air from cylinder′s top valve
when filling the cylinder with refrigerant. Also, the accuracy of the cylinder is generally less than that of an
electronic scale or of quality recycle/recharge equipment.
Shut-off valve rotation A/C service valve
Clockwise Open
Counterclockwise Close
RHA273D
RHA274D

REFRIGERATION SYSTEM
ATC-21
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Revision: 2004 November 2004 FX35/FX45
REFRIGERATION SYSTEMPFP:KA990
Refrigerant CycleAJS00146
REFRIGERANT FLOW
The refrigerant flows in the standard pattern, that is, through the compressor, the condenser with liquid tank,
through the evaporator, and back to the compressor. The refrigerant evaporation through the evaporator coil is
controlled by an externally equalized expansion valve, located inside the evaporator case.
FREEZE PROTECTION
Under usual operating conditions, when the A/C is switched on, the compressor runs continuously, and the
evaporator pressure, and therefore, temperature is controlled by the compressor to prevent freeze up.
Refrigerant System ProtectionAJS00147
REFRIGERANT PRESSURE SENSOR
The refrigerant system is protected against excessively high- or low-pressure by the refrigerant pressure sen-
sor, located on the condenser. If the system pressure rises above, or falls below the specifications, the refrig-
erant pressure sensor detects the pressure inside the refrigerant line and sends the voltage signal to the ECM.
ECM makes the A/C relay go OFF and stops the compressor when pressure on the high-pressure side
detected by refrigerant pressure sensor is over about 2,746 kPa (28 kg/cm
2 , 398 psi), or below about 134 kPa
(1.4 kg/cm
2 , 20 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 increases to an unusual level [more than 3,727 kPa (38 kg/cm
2
, 540 psi)], the release port on the pressure relief valve automatically opens and releases refrigerant into the
atmosphere.
RJIA0849E

ATC-22
REFRIGERATION SYSTEM
Revision: 2004 November 2004 FX35/FX45
V-6 Variable Displacement CompressorAJS001BE
GENERAL INFORMATION
1. The V-6 variable compressor differs from previous units. The vent temperatures of the V-6 variable com-
pressor do not drop too far below 5°C (41°F) when:
Evaporator intake air temperature is less than 20°C (68°F).
Engine is running at speeds less than 1,500 rpm.
This is because the V-6 compressor provides a means of “capacity” control.
2. The V-6 variable compressor provides refrigerant control under varying conditions. During cold winters, it
may not produce high refrigerant pressure discharge (compared to previous units) when used with air
conditioning systems.
3. A “clanking” sound may occasionally be heard during refrigerant charge. The sound indicates that the tilt
angle of the wobble (swash) plate has changed and is not a malfunction.
4. For air conditioning systems with the V-6 compressor, the clutch remains engaged unless: the system
main switch, fan switch or ignition switch is turned OFF. When ambient (outside) temperatures are low or
when the amount of refrigerant is insufficient, the clutch is disengaged to protect the compressor.

ATC-24
REFRIGERATION SYSTEM
Revision: 2004 November 2004 FX35/FX45
Operation
1. Operation Control Valve
–By changing high-pressure valve lift amount, built-in compressor control valve executes the following:
 Controls high-pressure valve discharge amount.
 Changes crankcase pressure in compressor.
 Changes angle of wobble (swash) plate.
–Amount of high-pressure valve loft is determined by factors below.
 Low-pressure applied to diaphragm
 Spring load of set spring
 Balance of magnetic force generated in magnet coil
–Electronic control valve (ECV) magnet coil receives electric signal (duty control) from unified meter and A/
C amp. (Auto amp.) Then, magnetic force generated by electric current is changed to control high-pres-
sure valve lift amount.
2. Maximum Cooling
High-pressure valve is closed by magnetic force generated by electric signal sent from unified meter and
A/C amp. At this time, cylinder moves full stroke due to pressure balance between inside crankcase (Pc)
and suction line (Ps).
Under this condition, the wobble (swash) plate is set to the maximum stroke position.
3. Capacity Control
When no electric signal is sent from unified meter and A/C amp. (current: OFF), high-pressure valve is
opened by spring force.
Since suction pressure is low, it makes the suction port close and the discharge port open. Thus, crank-
case pressure becomes high as high-pressure enters the crankcase.
–The force acts around the journal pin near the wobble (swash) plate, and is generated by the pressure dif-
ference before and behind the piston.
–The drive lug and journal pin are located where the piston generates the highest pressure. Piston pres-
sure is between suction pressure Ps and discharge pressure Pd, which is near suction pressure Ps. If
crankcase pressure Pc rises due to capacity control, the force around the journal pin makes the wobble
(swash) plate angle decrease and also the piston stroke decrease. In other words, crankcase pressure
RJIA0851E

LUBRICANT
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Revision: 2004 November 2004 FX35/FX45
LUBRICANTPFP:KLG00
Maintenance of Lubricant Quantity in CompressorAJS00149
The lubricant in the compressor circulates through the system with the refrigerant. Add lubricant to compres-
sor when replacing any component or after a large refrigerant leakage occurred. It is important to maintain the
specified amount.
If lubricant quantity is not maintained properly, the following malfunctions may result:

Lack of lubricant: May lead to a seized compressor

Excessive lubricant: Inadequate cooling (thermal exchange interference)
LUBRICANT
LUBRICANT RETURN OPERATION
Adjust the lubricant quantity according to the test group shown below.
1. CHECK LUBRICANT RETURN OPERATION
Can lubricant return operation be performed?

A/C system works properly.

There is no evidence of a large amount of lubricant leakage.
CAUTION:
If excessive lubricant leakage is noted, do not perform the lubricant return operation.
YES or NO
YES >> GO TO 2.
NO >> GO TO 3.
2. PERFORM LUBRICANT RETURN OPERATION, PROCEEDING AS FOLLOWS:
1. Start engine, and set the following conditions:
–Test condition
Engine speed: Idling to 1,200 rpm
A/C switch: ON
Blower speed: Max. position
Temp. control: Optional [Set so that intake air temperature is 25 to 30°C (77 to 86°F).]
Intake position: Recirculation (REC)
2. Perform lubricant return operation for about 10 minutes.
3. Stop engine.
>> GO TO 3.
3. CHECK REPLACEMENT PART
Should the compressor be replaced?
YES >> GO TO AT C - 2 9 , "LUBRICANT ADJUSTING PROCEDURE FOR COMPRESSOR REPLACE-
MENT" .
NO >> GO TO AT C - 2 8 , "
LUBRICANT ADJUSTING PROCEDURE FOR COMPONENTS REPLACE-
MENT EXCEPT COMPRESSOR" . Name : NISSAN A/C System Oil Type S
Part number : KLH00-PAGS0

ATC-30
AIR CONDITIONER CONTROL
Revision: 2004 November 2004 FX35/FX45
AIR CONDITIONER CONTROLPFP:27500
Description of Air Conditioner LAN Control SystemAJS0014A
The LAN (Local Area Network) system consists of unified meter and A/C amp., mode door motor, air mix door
motor and intake door motor.
A configuration of these components is shown in the diagram below.
System ConstructionAJS0014B
A small network is constructed between the unified meter and A/C amp., air mix door motor, 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 the each door motor.
Addresses, motor opening angle signals, motor stop signals 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 motor, mode door motor and 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 motor 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 are compared by the LCUs in each motor with the existing decision and opening
angles. Subsequently, HOT/COLD, DEFROST/VENT or FRESH/RECIRCULATION operation is selected. The
new selection data is returned to the unified meter and A/C amp.
SJIA0262E
RJIA1747E

AIR CONDITIONER CONTROL
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Revision: 2004 November 2004 FX35/FX45
TRANSMISSION DATA AND TRANSMISSION ORDER
Unified meter and A/C amp. data is transmitted consecutively to each of the door motors following the form
shown in figure below.
Start:
Initial compulsory signal sent to each of the door motors.
Address:
Data sent from the unified meter and A/C amp. is 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 decision. If the opening angle data is usual, door control
begins.
If an error exists, the received data is 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:
Procedure by which sent and received data is checked for errors. Error data is then compiled. The error check
prevents corrupted data from being used by the air mix door motor, mode door motor and intake door motor.
Error data can be related to the following symptoms.

Unusual electrical frequency

Poor electrical connections

Signal leakage from transmission lines

Signal level fluctuation
RJIA1748E