NISSAN ALMERA N16 2003 Electronic Repair Manual

Operation=NJHA0207S021. Operation Control ValveNJHA0207S0201Operation control valve is located in the suction port (low-pressure) side, and opens or closes in response to
changes in refrigerant suction pressure.
Operation of the valve controls the internal pressure of the crankcase.
The angle of the swash plate is controlled between the crankcase’s internal pressure and the piston cylinder
pressure.
2. Maximum Cooling
NJHA0207S0202Refrigerant pressure on the low-pressure side increases with an increasein heat loads.
When this occurs, the control valve’s bellows compress to open the low-pressure side valve and close the
high-pressure side valve.
This causes the following pressure changes:
the crankcase’s internal pressure to equal the pressure on the low-pressure side;
the cylinder’s internal pressure to be greater than the crankcase’s internal pressure.
Under this condition, the swash plate is set to the maximum stroke position.
RHA473C
GI
MA
EM
LC
EC
FE
CL
MT
AT
AX
SU
BR
ST
RS
BT
SC
EL
IDX
DESCRIPTIONMANUAL
CSV613 Variable Displacement Compressor (Cont’d)
HA-15

3. Capacity Control=NJHA0207S0203Refrigerant pressure on suction side is low during high speed driving or when ambient or interior tempera-
ture is low.
The bellows expands when refrigerant pressure on the suction pressure side drops below approximately
177 kPa (1.77 bar, 1.8 kg/cm
2, 26 psi).
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 swash plate, and is generatedby the pressure difference
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 swash
plate angle decrease and also the piston stroke decrease. In other words, crankcase pressure increase
triggers pressure difference between the piston and the crankcase. The pressure difference changes the
angle of the swash plate.
RHA474C
DESCRIPTIONMANUAL
CSV613 Variable Displacement Compressor (Cont’d)
HA-16

Component LayoutNJHA0122
RHA589H
GI
MA
EM
LC
EC
FE
CL
MT
AT
AX
SU
BR
ST
RS
BT
SC
EL
IDX
DESCRIPTIONMANUAL
Component Layout
HA-17

Control OperationNJHA0123
RHA247I
FAN CONTROL SWITCHNJHA0123S01This switch turns the fan ON and OFF, and controls fan speed.
MODE CONTROL KNOBNJHA0123S02This knob controls the outlet air flow.
TEMPERATURE CONTROL KNOBNJHA0123S03This knob allows you to adjust the temperature of the discharge air.
REAR WINDOW DEFOGGER SWITCHNJHA0123S07When illumination is ON, rear window is defogged.
AIR CONDITIONER (A/C) SWITCHNJHA0123S05The air conditioner switch controls the A/C system. When the switch is depressed with the fan ON, the com-
pressor will turn ON. The indicator lamp will also light.
The air conditioner cooling function operates only when the engine is running.
RECIRCULATION (REC) SWITCHNJHA0123S08Recirculation (REC) position: Interior air is recirculated inside the vehicle. (The indicator lamp will light.) The
A/C system operates at maximum performance when the REC switch is ON.
Fresh (FRE) position: Outlet air is drawn into the passenger compartment.(The indicator lamp will not light.)
DESCRIPTIONMANUAL
Control Operation
HA-18

Discharge Air FlowNJHA0124
RHA248I
GI
MA
EM
LC
EC
FE
CL
MT
AT
AX
SU
BR
ST
RS
BT
SC
EL
IDX
DESCRIPTIONMANUAL
Discharge Air Flow
HA-19

System DescriptionNJHA0125SWITCHES AND THEIR CONTROL FUNCTIONSNJHA0125S01
Knob/SwitchKnob/Switch position
Compressor
A/C VENT B/L FOOT D/F DEF REC FRE
A/CON*1
Mode
—
—
—
—
—
Intake
—
—
*1: Compressor is operated by ECM.
DESCRIPTIONMANUAL
System Description
HA-20

Component LocationNJHA0126ENGINE COMPARTMENTNJHA0126S01
RHA249I
GI
MA
EM
LC
EC
FE
CL
MT
AT
AX
SU
BR
ST
RS
BT
SC
EL
IDX
TROUBLE DIAGNOSESMANUAL
Component Location
HA-21

PASSENGER COMPARTMENTNJHA0126S02
RHA250I
TROUBLE DIAGNOSESMANUAL
Component Location (Cont’d)
HA-22

Wiring Diagram — HeaterNJHA0202
YHA460
GI
MA
EM
LC
EC
FE
CL
MT
AT
AX
SU
BR
ST
RS
BT
SC
EL
IDX
TROUBLE DIAGNOSESMANUAL
Wiring Diagram — Heater
HA-23

Circuit Diagram — Air ConditionerNJHA0127
YHA461
TROUBLE DIAGNOSESMANUAL
Circuit Diagram — Air Conditioner
HA-24