Nissan Titan. Manual - part 400

REFRIGERATION SYSTEM

HAC-105

< SYSTEM DESCRIPTION >

[MANUAL A/C (TYPE 1)]

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REFRIGERATION SYSTEM

Refrigerant Cycle

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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 coils

are controlled by externally equalized expansion valve, located inside the evaporator case.

Refrigerant System Protection

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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

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, 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/

HAC-106

< SYSTEM DESCRIPTION >

[MANUAL A/C (TYPE 1)]

REFRIGERATION SYSTEM

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

the atmosphere.

WJIA1347E

MANUAL AIR CONDITIONER SYSTEM

HAC-107

< SYSTEM DESCRIPTION >

[MANUAL A/C (TYPE 1)]

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MANUAL AIR CONDITIONER SYSTEM

Control System Diagram

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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

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CONTROL OPERATION

Front air control

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HAC-108

< SYSTEM DESCRIPTION >

[MANUAL A/C (TYPE 1)]

MANUAL AIR CONDITIONER SYSTEM

TEMPERATURE CONTROL DIAL

Increases or decreases the set temperature.

RECIRCULATION (

) SWITCH

• When REC switch is ON, REC switch indicator turns ON, and air inlet is set to REC.

• When REC switch is turned OFF, or when compressor is turned from ON to OFF, REC switch is automati-

cally turned OFF. REC mode can be re-entered by pressing REC switch again.

• REC switch is not operated when DEF switch is turned ON, at the D/F position, or in floor position.

DEFROSTER (

) SWITCH

Positions the air outlet doors to the defrost position. Also positions the intake doors to the outside air position,

and turns A/C compressor ON.

REAR WINDOW DEFOGGER SWITCH (IF EQUIPPED)

When switch is ON, rear window and door mirrors are defogged.

OFF SWITCH

The compressor and blower are OFF, the intake doors are set to the outside air position, and the air outlet

doors are set to the foot (75% foot and 25% defrost) position.

BLOWER CONTROL DIAL/OFF SWITCH

• The blower speed is manually controlled with this dial.

• The compressor and blower are OFF, the intake doors are set to the outside air position, and the air outlet

doors are set to the foot position.

A/C SWITCH

The compressor is ON or OFF.

(Pressing the A/C switch when the AUTO switch is ON will turn off the A/C switch and compressor.)

MODE SWITCHES

Controls the air discharge outlets.

MAGNET CLUTCH CONTROL

When A/C switch or DEF switch is pressed, front air control inputs compressor ON signal to BCM.

BCM sends compressor ON signal to ECM and front air control, via CAN communication line.

ECM judges whether compressor can be turned ON, based on each sensor status (refrigerant pressure sen-

sor signal, throttle angle sensor, etc.). If it judges compressor can be turned ON, it sends compressor ON sig-

nal to IPDM E/R, via CAN communication line.

Upon receipt of compressor ON signal from ECM, IPDM E/R turns air conditioner relay ON to operate com-

pressor.

AWIIA1081GB