cooling INFINITI FX35 2004 User Guide

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
ATC-27
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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-42
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
How to Perform Trouble Diagnosis for Quick and Accurate RepairAJS0014K
WORK FLOW
SYMPTOM TABLE
*1ATC-61, "Operational Check"
SHA900E
Symptom Reference Page
A/C system does not come on. Go to Trouble Diagnosis Procedure for A/C System.AT C - 6 3 , "
Power
Supply and Ground
Circuit for Auto
Amp."
A/C system cannot be controlled.
Go to Integrated Display System.

Go to Navigation System.AV-78, "
Trouble
Diagnosis Chart by
Symptom" (Without
navigation system)
or AV-84, "
A/C and
AV Switch Does Not
Operate" (With nav-
igation system)
Air outlet does not change.
Go to Trouble Diagnosis Procedure for Mode Door Motor. (LAN)AT C - 7 0 , "
Mode
Door Motor Circuit"Mode door motor does not operate normally.
Discharge air temperature does not change.
Go to Trouble Diagnosis Procedure for Air Mix Door Motor.
(LAN)ATC-73, "
Air Mix
Door Motor Circuit"Air mix door motor does not operate nor-
mally.
Intake door does not change.
Go to Trouble Diagnosis Procedure for Intake Door Motor. (LAN)ATC-76, "
Intake
Door Motor Circuit"Intake door motor does not operate nor-
mally.
Blower motor operation is malfunctioning.
Go to Trouble Diagnosis Procedure for Blower Motor.ATC-79, "
Blower
Motor Circuit"Blower motor operation is malfunctioning
under out of starting fan speed control.
Magnet clutch does not engage. Go to Trouble Diagnosis Procedure for Magnet Clutch.ATC-84, "
Magnet
Clutch Circuit"
Insufficient coolingGo to Trouble Diagnosis Procedure for Insufficient Cooling.AT C - 9 1 , "
Insufficient
Cooling"
Go to Diagnostic Procedure for Insufficient Cooling.AT C - 9 8 , "
DIAG-
NOSTIC PROCE-
DURE FOR
INSUFFICIENT
COOLING"
Insufficient heating Go to Trouble Diagnosis Procedure for Insufficient Heating.ATC-100, "Insuffi-
cient Heating"
Noise Go to Trouble Diagnosis Procedure for Noise.ATC-101, "Noise"
Self-diagnosis cannot be performed. Go to Trouble Diagnosis Procedure for Self-diagnosis.ATC-102, "Self-
diagnosis"
Memory function does not operate. Go to Trouble Diagnosis Procedure for Memory Function.ATC-103, "Memory
Function"

ATC-62
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
CHECKING RECIRCULATION
1. Press recirculation (REC) switch one time. Recirculation indica-
tor should illuminate.
2. Press fresh (FRE) switch one time. Fresh indicator should illumi-
nate.
3. Listen for intake door position change (you should hear blower
sound change slightly).
If NG, go to trouble diagnosis procedure for AT C - 7 6 , "
Intake Door
Motor Circuit" .
If OK, continue the check.
NOTE:
Confirm that the compressor clutch is engaged (sound or visual
inspection) and intake door position is at FRESH when the DEF or D/F is selected.
CHECKING TEMPERATURE DECREASE
1. Press temperature (DOWN) switch (driver side) until 18°C
(60°F) is displayed.
2. Check for cold air at discharge air outlets.
If NG, go to trouble diagnosis procedure for AT C - 9 1 , "
Insufficient
Cooling" .
If OK, continue the check.
CHECKING TEMPERATURE INCREASE
1. Press temperature (UP) switch (driver side) until 32°C (90°F) is
displayed.
2. Check for hot air at discharge air outlets.
If NG, go to trouble diagnosis procedure for ATC-100, "
Insufficient
Heating" .
If OK, continue the check.
CHECK A/C SWITCH
1. Press AUTO switch and A/C switch.
2. A/C switch indicator will turn ON.

Confirm that the compressor clutch engages (sound or visual
inspection).
If NG, go to trouble diagnosis procedure for AT C - 8 4 , "
Magnet Clutch
Circuit" .
If OK, continue the check.
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ATC-72
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
Mode Door Control Specification
COMPONENT DESCRIPTION
Mode Door Motor
The mode door motor is attached to the heater & cooling unit. It
rotates so that air is discharged from the outlet set by the unified
meter and A/C amp. Motor rotation is conveyed to a link which acti-
vates the mode door.
DIAGNOSTIC PROCEDURE FOR MODE DOOR MOTOR
SYMPTOM: Mode door motor does not operate normally.
Perform diagnostic procedure for AT C - 6 6 , "
DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT" .
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TROUBLE DIAGNOSIS
ATC-75
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Revision: 2004 November 2004 FX35/FX45
COMPONENT DESCRIPTION
Air Mix Door Motor
The air mix door motor is attached to the heater & cooling unit. It
rotates so that the air mix door is opened or closed to a position set
by the unified meter and A/C amp. Motor rotation is conveyed
through a shaft and the air mix door position is then fed back to the
unified meter and A/C amp. by PBR built-in air mix door motor.
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR
Perform diagnostic procedure for AT C - 6 6 , "DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT" .
Air Mix Door Motor PBR CircuitAJS0014V
SYMPTOM:

Discharge air temperature does not change.

PBR circuit is open or shorted.
DIAGNOSTIC PROCEDURE FOR AIR MIX DOOR PBR
Perform diagnostic procedure for AT C - 6 6 , "DIAGNOSTIC PROCEDURE FOR LAN CIRCUIT" .
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TROUBLE DIAGNOSIS
ATC-91
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Revision: 2004 November 2004 FX35/FX45
Insufficient CoolingAJS0014Z
SYMPTOM: Insufficient cooling
INSPECTION FLOW
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ATC-96
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
TROUBLE DIAGNOSIS FOR UNUSUAL PRESSURE
Whenever system′s high and/or low side pressure(s) is/are unusual, diagnose using a manifold gauge. The
marker above the gauge scale in the following tables indicates the standard (usual) pressure range. Since the
standard (usual) pressure, however, differs from vehicle to vehicle, refer to above table (Ambient air tempera-
ture-to-operating pressure table).
Both High- and Low-pressure Sides are Too High
High-pressure Side is Too High and Low-pressure Side is Too Low
Gauge indication Refrigerant cycle Probable cause Corrective action
Both high- and low-pressure sides
are too high.Pressure is reduced soon
after water is splashed on
condenser.Excessive refrigerant charge
in refrigeration cycleReduce refrigerant until speci-
fied pressure is obtained.
Air suction by cooling fan is
insufficient.Insufficient condenser cooling
performance
↓
1. Condenser fins are clogged.
2. Improper fan rotation of
cooling fan

Clean condenser.

Check and repair cooling fan
as necessary.

Low-pressure pipe is not
cold.

When compressor is
stopped high-pressure
value quickly drops by
approximately 196 kPa (2
kg/cm
2 , 28 psi). It then
decreases gradually there-
after.Poor heat exchange in con-
denser
(After compressor operation
stops, high-pressure
decreases too slowly.)
↓
Air in refrigeration cycleEvacuate repeatedly and
recharge system.
Engine tends to overheat.Engine cooling systems mal-
function.Check and repair each engine
cooling system.

An area of the low-pres-
sure pipe is colder than
areas near the evaporator
outlet.

Plates are sometimes cov-
ered with frost.

Excessive liquid refrigerant
on low-pressure side

Excessive refrigerant dis-
charge flow

Expansion valve is open a
little compared with the
specification.
↓
Improper expansion valve
adjustmentReplace expansion valve.
AC359A
Gauge indication Refrigerant cycle Probable cause Corrective action
High-pressure side is too high and
low-pressure side is too low.
Upper side of condenser and
high-pressure side are hot,
however, liquid tank is not so
hot.High-pressure tube or parts
located between compressor
and condenser are clogged or
crushed.

Check and repair or replace
malfunctioning parts.

Check lubricant for contami-
nation.
AC360A

ATC-98
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
Low-pressure Side Sometimes Becomes Negative
Low-pressure Side Becomes Negative
DIAGNOSTIC PROCEDURE FOR INSUFFICIENT COOLING
SYMPTOM: Insufficient cooling
1. CHECK POWER SUPPLY FOR ECV (ELECTRONIC CONTROL VALVE)
1. Disconnect compressor (ECV) connector.
2. Turn ignition switch ON.
3. Check voltage between compressor harness connector F6 ter-
minal 2 (G) and ground.
OK or NG
OK >> GO TO 2.
NG >> Check power supply circuit and 10A fuse [No. 12,
located in the fuse block (J/B)]. Refer to PG-83, "
FUSE
BLOCK - JUNCTION BOX (J/B)" .
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side sometimes
becomes negative.

Air conditioning system
does not function and does
not cyclically cool the com-
partment air.

The system constantly func-
tions for a certain period of
time after compressor is
stopped and restarted.Refrigerant does not dis-
charge cyclically.
↓
Moisture is frozen at expan-
sion valve outlet and inlet.
↓
Water is mixed with refriger-
ant.

Drain water from refrigerant
or replace refrigerant.

Replace liquid tank.
AC354A
Gauge indication Refrigerant cycle Probable cause Corrective action
Low-pressure side becomes nega-
tive.
Liquid tank or front/rear side of
expansion valve′s pipe is
frosted or dewed.High-pressure side is closed
and refrigerant does not flow.
↓
Expansion valve or liquid tank
is frosted.Leave the system at rest until
no frost is present. Start it
again to check whether or not
the malfunction is caused by
water or foreign particles.

If water is the cause, initially
cooling is okay. Then the
water freezes causing a
blockage. Drain water from
refrigerant or replace refrig-
erant.

If due to foreign particles,
remove expansion valve
and remove the particles
with dry and compressed air
(not shop air).

If either of the above meth-
ods cannot correct the mal-
function, replace expansion
valve.

Replace liquid tank.

Check lubricant for contami-
nation.
AC362A
2 – ground : Battery voltage
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TROUBLE DIAGNOSIS
ATC-107
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Revision: 2004 November 2004 FX35/FX45
In-vehicle Sensor CircuitAJS00155
COMPONENT DESCRIPTION
In-vehicle Sensor
The in-vehicle sensor is located on instrument driver lower panel. It
converts variations in temperature of compartment air drawn from
the aspirator into a resistance value. It is then input into the unified
meter and A/C amp.
Aspirator
The aspirator is located on driver′s side of heater & cooling unit. It
produces vacuum pressure due to air discharged from the heater &
cooling unit, continuously taking compartment air in the aspirator.
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