Infiniti EX35. Manual - part 886

DIAGNOSIS AND REPAIR WORKFLOW

HA-3

< BASIC INSPECTION >

C

D

E

F

G

H

J

K

L

M

A

B

HA

N

O

P

BASIC INSPECTION

DIAGNOSIS AND REPAIR WORKFLOW

Work Flow

INFOID:0000000003545446

DETAILED FLOW

1.

LISTEN TO CUSTOMER COMPLAINT

Listen to customer complaint. (Get detailed information about the conditions and environment when the symp-
tom occurs.)

>> GO TO 2.

2.

VERIFY THE SYMPTOM WITH OPERATIONAL CHECK

Verify the symptom with operational check. Refer to 

HAC-6, "WITHOUT LEFT AND RIGHT VENTILATION

TEMPERATURE SEPARATELY CONTROL SYSTEM : Description & Inspection"

 (Without left and right venti-

lation temperature separately control system) or 

HAC-11, "WITH LEFT AND RIGHT VENTILATION TEMPER-

ATURE SEPARATELY CONTROL SYSTEM : Description & Inspection"

 (With left and right ventilation

temperature separately control system).

>> GO TO 3.

3.

GO TO APPROPRIATE TROUBLE DIAGNOSIS

Go to appropriate trouble diagnosis (Refer to 

HAC-132, "Diagnosis Chart By Symptom"

 below).

>> GO TO 4.

4.

REPAIR OR REPLACE

Repair or replace the specific parts.

>> GO TO 5.

5.

FINAL CHECK

Final check.

Is the inspection result normal?

YES

>> CHECK OUT

NO

>> GO TO 3.

HA-4

< FUNCTION DIAGNOSIS >

REFRIGERATION SYSTEM

FUNCTION DIAGNOSIS

REFRIGERATION SYSTEM

System Diagram

INFOID:0000000003545447

System Description

INFOID:0000000003545448

REFRIGERANT CYCLE

Refrigerant Flow

The refrigerant flows from the compressor, through the condenser with liquid tank, through the evaporator, and
back to the compressor. The refrigerant evaporation in the evaporator is controlled by an externally equalized
expansion valve, located inside the evaporator case.

Freeze Protection

To prevent evaporator from freezing up, the evaporator air temperature is monitored, and the voltage signal to
the unified meter and A/C 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 sen-
sor, 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 specifications.
ECM makes the A/C relay go OFF and stops the compressor when pressure on the high-pressure side
detected by refrigerant pressure sensor is over approximately 3,119 kPa (31.8 kg/cm

2

, 452 psi), or below

approximately 118 kPa (1.2 kg/cm

2

, 17 psi).

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 3,628 kPa (37 kg/cm

2

,

526 psi)].

RJIA1552E

REFRIGERATION SYSTEM

HA-5

< FUNCTION DIAGNOSIS >

C

D

E

F

G

H

J

K

L

M

A

B

HA

N

O

P

Component Parts Location

INFOID:0000000003545449

1.

Refrigerant pressure sensor

2.

Liquid tank

3.

Condenser

4.

Compressor

JPIIA0713ZZ

HA-6

< FUNCTION DIAGNOSIS >

REFRIGERATION SYSTEM

Component Description

INFOID:0000000003545450

1.

Expansion valve

2.

Evaporator

3.

Blower motor

JPIIA0714ZZ

Component

Description

Compressor

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

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-471, "Description"

.

Expansion valve

Transforms high-pressure liquid refrigerant to mist form low-pressure liquid refrigerant by drawing 
function.

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.

Blower motor

Takes in air in the vehicle or fresh outside air, provides it forcedly to the air conditioner, and conveys 
it inside the vehicle.