Nissan Pathfinder. Manual - part 675

PREPARATION

HA-11

< PREPARATION >

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Sealant and/or Oil

INFOID:0000000009176719

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(J-39699)
Refrigerant weight scale

For measuring of refrigerant
Fitting size-Thread size
• 1/2”-16 ACME

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(J-39649)
Vacuum pump
(Including the isolator valve)

Capacity:
• Air displacement: 4 CFM
• Micron rating: 20 microns
• Oil capacity: 482 g (17 oz)

Fitting size-Thread size

• 1/2”-16 ACME

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(J-46534)
Trim tool set

Removing trim components

(Kent-Moore No.)
Tool name

Description

S-NT200

S-NT203

AWJIA0483ZZ

Tool number
(Kent-Moore No.)
Tool name

Description 

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HFC-134a (R-134a) Refrigerant

Container color: Light blue
Container marking: HFC-134a (R-
134a)
Fitting size: Thread size
• large container 1/2”-16 ACME

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NISSAN A/C System Oil Type S

Type: Poly alkylene glycol oil (PAG), 
type S (DH-PS)
Application: HFC-134a (R-134a) 
swash plate compressors
Capacity: 40 m  (1.4 US fl oz, 1.4 Imp 
fl oz) 

S-NT196

JMIIA1759ZZ

HA-12

< SYSTEM DESCRIPTION >

COMPONENT PARTS

SYSTEM DESCRIPTION

COMPONENT PARTS

Component Parts Location

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Component Description

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1.

Compressor

2.

Condenser

3.

Liquid tank

4.

Refrigerant pressure sensor

5.

Evaporator

6.

Expansion valve

Component

Description

Compressor

Intakes, compresses and discharges refrigerant to circulate refrigerant inside the refrigerant system.

Condenser

Cools refrigerant discharged from compressor and transforms it to liquid refrigerant.

Liquid tank

Eliminates foreign matter in refrigerant and stores temporarily liquid refrigerant.

Refrigerant pressure sensor

Refer to 

EC-448, "Component Function Check"

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Expansion valve

Transforms high-pressure liquid refrigerant to mist form low-pressure liquid refrigerant.

Evaporator

The mist form liquid refrigerant transforms to gas by evaporation by the air conveyed from blower 
motor. The air is cooled by the heat by evaporation.

SYSTEM

HA-13

< SYSTEM DESCRIPTION >

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SYSTEM

System Diagram

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System Description

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REFRIGERANT CYCLE

Refrigerant Flow

The refrigerant from the compressor flows through the condenser and liquid tank, evaporator, and returns to

the compressor. The refrigerant evaporation in the evaporator is controlled by an expansion valve.

1.

Pressure relief valve

2.

Compressor

3.

Condenser

4.

Refrigerant pressure sensor

5.

Front blower motor

6.

Front evaporator and expansion valve assembly

7.

Liquid tank

8.

Rear expansion valve

9.

Rear evaporator

10. Rear blower motor

A.

High-pressure gas

B.

High-pressure liquid

C.

Low-pressure liquid

D.

Low-pressure gas

E.

Outside air

AWIIA1517ZZ

HA-14

< SYSTEM DESCRIPTION >

SYSTEM

Freeze Protection

To prevent evaporator from freezing up, the evaporator air temperature is monitored and the voltage signal to

the A/C auto amp. makes the A/C relay go OFF and stop the compressor.

REFRIGERANT SYSTEM PROTECTION

Refrigerant Pressure Sensor

• The refrigerant system is protected against excessively high or low pressures by the refrigerant pressure

sensor, located on the liquid tank. The refrigerant pressure sensor detects the pressure inside the refrigerant

line and sends the voltage signal to the ECM if the system pressure rises above or falls below the specifica-

tions. 

• ECM turns the A/C relay to OFF and stops the compressor when the high-pressure side detected by refriger-

ant pressure sensor to have the following conditions:

- Approximately 3,120 kPa (31.8 kg/cm

2

, 452 psi) or more (Engine speed is 1,500 rpm or more.)

- Approximately 2,740 kPa (27.9 kg/cm

2

, 397 psi) or more (Engine speed is less than 1,500 rpm.)

- Approximately 120 kPa (1.2 kg/cm

2

, 17 psi) or less

Pressure Relief Valve

The refrigerant system is also protected by a pressure relief valve, located in the rear head of the compressor.

The release port on the pressure relief valve automatically opens and releases refrigerant into the atmosphere

when the pressure of refrigerant in the system increases to an unusual level [more than 3,800 kPa (38.8 kg/
cm

2

, 551 psi)].