Nissan Frontier. Manual - part 902

HAC-162

< SYSTEM DESCRIPTION >

[MANUAL A/C (TYPE 2)]

FUNCTION INFORMATION

FUNCTION INFORMATION

Component Part Location

INFOID:0000000009478375

ENGINE COMPARTMENT

WJIA1489E

FUNCTION INFORMATION

HAC-163

< SYSTEM DESCRIPTION >

[MANUAL A/C (TYPE 2)]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

PASSENGER COMPARTMENT

⇒

:Front

1.

Front air control M49

2.

Intake sensor M146

3.

Intake door motor M58

4.

Front blower motor resistor M122

5.

Mode door motor M142

6.

Air mix door motor M147

AWIIA0724ZZ

HAC-164

< SYSTEM DESCRIPTION >

[MANUAL A/C (TYPE 2)]

REFRIGERATION SYSTEM

REFRIGERATION SYSTEM

Refrigerant Cycle

INFOID:0000000009478376

REFRIGERANT FLOW

The refrigerant flows in the standard pattern. Refrigerant flows through the compressor, condenser, liquid tank,

expansion valve, 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

The compressor cycles on and off to maintain the evaporator temperature within a specified range. When the

evaporator coil temperature falls below a specified point, the intake sensor interrupts the compressor opera-

tion. When the evaporator coil temperature rises above the specification, the intake sensor allows compressor

operation.

Refrigerant System Protection

INFOID:0000000009478377

REFRIGERANT PRESSURE SENSOR

The refrigerant system is protected against excessively high- 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 pressure 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 increases to an abnormal level [more than 2,990 kPa (30.5 kg/
cm

2

, 433.6 psi)], the release port on the pressure relief valve automatically opens and releases refrigerant into

the atmosphere.

WJIA1482E

MANUAL AIR CONDITIONER SYSTEM

HAC-165

< SYSTEM DESCRIPTION >

[MANUAL A/C (TYPE 2)]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

MANUAL AIR CONDITIONER SYSTEM

Control System Diagram

INFOID:0000000009478378

CONTROL SYSTEM

The control system consists of input sensors, switches, the front air control (microcomputer) and outputs.

The relationship of these components is shown in the figure below:

Control System Description

INFOID:0000000009478379

CONTROL OPERATION

Front air control

AWIIA0730GB

WJIA1510E