Nissan Frontier. Manual - part 864

HAC-10

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONER]

FUNCTION INFORMATION

Symptom Table

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1.

Front air control M52, M56

2.

In-vehicle sensor M34

3.

Intake sensor M146

4.

Intake door motor M58

5.

Variable blower control (front) 
M121

6.

Air mix door motor (Passenger) M131

7.

Mode door motor M142

8.

Air mix door motor (driver) M148

9.

Optical sensor M14

⇐

:Front

Symptom

Reference Page

A/C system does not come on.

Go to Trouble Diagnosis Procedure for A/C System.

HAC-59

A/C system cannot be controlled.

Go to Self-diagnosis Function.

HAC-20

Air outlet does not change.

Go to Trouble Diagnosis Procedure for Mode Door Motor.

HAC-22

Mode door motor is malfunctioning.

Discharge air temperature does not change.

Go to Trouble Diagnosis Procedure for Air Mix Door Motor.

HAC-26

Air mix door motor is malfunctioning.

Intake door does not change.

Go to Trouble Diagnosis Procedure for Intake Door Motor.

HAC-34

Intake door motor is malfunctioning.

Front blower motor operation is malfunction-
ing.

Go to Trouble Diagnosis Procedure for Front Blower Motor.

HAC-37

Magnet clutch does not engage.

Go to Trouble Diagnosis Procedure for Magnet Clutch.

HAC-43

Insufficient cooling

Go to Trouble Diagnosis Procedure for Insufficient Cooling.

HAC-73

Insufficient heating

Go to Trouble Diagnosis Procedure for Insufficient Heating.

HAC-81

Noise

Go to Trouble Diagnosis Procedure for Noise.

HAC-83

Self-diagnosis cannot be performed.

Go to Trouble Diagnosis Procedure for Self-diagnosis.

HAC-20

Memory function does not operate.

Go to Trouble Diagnosis Procedure for Memory Function.

HAC-85

REFRIGERATION SYSTEM

HAC-11

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONER]

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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

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/

HAC-12

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONER]

REFRIGERATION SYSTEM

cm

2

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

the atmosphere.

WJIA1347E

AUTOMATIC AIR CONDITIONER SYSTEM

HAC-13

< SYSTEM DESCRIPTION >

[AUTOMATIC AIR CONDITIONER]

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AUTOMATIC 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 with rear window defogger

ALIIA0754GB

AWIIA0937ZZ