Infiniti QX56 (Z62). Manual - part 769

DIAGNOSIS AND REPAIR WORKFLOW

HA-17

< BASIC INSPECTION >

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>> GO TO 2.

2.

SYMPTOM CHECK

Check the symptom from the customer's information. Check that any symptom occurs other than the inter-
viewed symptom.

Insufficient cooling/heating>>GO TO 3.
Refrigerant leakage>>GO TO 6.
Noise >> GO TO 7.

3.

CONTROL SYSTEM DIAGNOSIS

Perform the system diagnosis for the A/C control system. Refer to 

HAC-60, "Work Flow"

.

Is A/C control system normal?

YES

>> GO TO 4.

NO

>> GO TO 8.

4.

PERFORMANCE TEST

Perform the performance test. Check the operation of each part. Refer to 

HA-25, "Inspection"

.

>> GO TO 5.

5.

TROUBLE DIAGNOSIS FOR UNUSUAL PRESSURE

Diagnose using a manifold gauge whenever system's high and/or low side pressure(s) is/are unusual. Specify
the malfunctioning part. Refer to 

HA-27, "Symptom Table"

.

Low refrigerant charge>>GO TO 6.
Except above>>GO TO 8.

6.

CHECK REFRIGERANT FOR LEAKAGES

Check refrigerant for leakages. Specify the malfunctioning part. Refer to 

HA-18, "Leak Test"

.

>> GO TO 8.

7.

TROUBLE DIAGNOSIS FOR NOISE

Perform trouble diagnosis for noise. Specify the malfunctioning part. Refer to 

HA-29, "Symptom Table"

.

>> GO TO 8.

8.

MALFUNCTION PART REPAIR

Repair or replace the malfunctioning part.

>> GO TO 9.

9.

REPAIR CHECK (OPERATION CHECK)

Check the operation of each part.
Does it operate normally?

YES

>> INSPECTION END

NO

>> GO TO 2.

HA-18

< BASIC INSPECTION >

REFRIGERANT

REFRIGERANT

Description

INFOID:0000000006276149

CONNECTION OF SERVICE TOOLS AND EQUIPMENT

Leak Test

INFOID:0000000006276150

CHECK REFRIGERANT LEAKAGE USING FLUORESCENT LEAK DETECTION DYE

1.

Install a fender cover (1).

2.

Wear UV safety goggles (2) provided with refrigerant dye leak detection kit.

3.

Connect power cable (4) of UV lamp (6) to positive and negative terminals of the battery (3).

4.

Press UV lamp switch (5) and check A/C system for refrigerant leakage. (Where refrigerant leakage
occurs, fluorescent leak detection dye appears in green color.)

WARNING:

1.

Shut-off valve

2.

A/C service valve

3.

Recovery/recycling/recharging 
equipment

4.

Refrigerant container (HFC-134a)

5.

Weight scale (J-39650)

6.

Vacuum pump (J-39649)

7.

Manifold gauge set (J-39183)

A.

Preferred (best) method

B.

Alternative method

C.

For charging

JSIIA0239ZZ

RJIA3815J

REFRIGERANT

HA-19

< BASIC INSPECTION >

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Never look directly into UV lamp light source.
NOTE:
• For continuous operating time of UV lamp, follow the manufacturer operating instructions.
• Illuminate piping joints from different angles using UV lamp and check that there is no leakage.
• Use a mirror in area that is difficult to see to check refrigerant leakage.
• Refrigerant leakage from evaporator can be detected by soaking cotton swab or a similar material with

drain hose water and illuminating it using UV lamp.

• Dust, dirt, and packing materials adhesive used for condenser, evaporator, and other locations may flu-

oresce. Be careful not to misidentify leakage.

5.

Repair or replace parts where refrigerant leakage occurs and wipe off fluorescent leak detection dye.
NOTE:
Completely wipe off fluorescent leak detection dye from gaps between parts, screw threads, and others
using a cotton swab or similar materials.

6.

Use a UV lamp to check that no fluorescent leak detection dye remains after finishing work.

WARNING:

Never look directly into UV lamp light source.
NOTE:
• For continuous operating time of UV lamp, follow the manufacturer operating instructions.
• Dust, dirt, and packing materials adhesive used for condenser, evaporator, and other locations may flu-

oresce. Be careful not to misidentify leakage.

CHECK REFRIGERANT LEAKAGE USING ELECTRICAL LEAK DETECTOR

WARNING:

Never check refrigerant leakage while the engine is running.

CAUTION:

Be careful of the following items so that inaccurate checks or misidentifications are avoided.
• Never allow refrigerant vapor, shop chemical vapors, cigarette smoke, or others around the vehicle.
• Always check refrigerant leakage in a low air flow environment so that refrigerant may not disperse

when leakage occurs.

1.

Stop the engine.

2.

Connect recovery/recycling/recharging equipment or manifold gauge set to A/C service valve.

3.

Check that A/C refrigerant pressure is 345 kPa (3.52 kg/cm

2

, 50 psi) or more when temperature is 16

°

C

(61

°

F) or more. When pressure is lower than the specified value, recycle refrigerant completely and fill

refrigerant to the specified level.
NOTE:
Leakages may not be detected if A/C refrigerant pressure is 345 kPa (3.52 kg/cm

2

, 50 psi) or less when

temperature is less than 16

°

C (61

°

F).

4.

Clean area where refrigerant leakage check is performed, and check refrigerant leakage along all sur-
faces of pipe connections and A/C system components using electrical leak detector probe.

CAUTION:

• Continue checking when a leakage is found. Always continue and complete checking along all

pipe connections and A/C system components for additional leakage.

• When a leakage is detected, clean leakage area using compressed air and check again.
• When checking leakage of cooling unit inside, always clean inside of drain hose so that the

probe surface may not be exposed to water or dirt.

NOTE:
• Always check leakage starting from high-pressure side and continue to low-pressure side.
• When checking leakage of cooling unit inside, operate blower fan motor for 15 minutes or more at the

maximum fan speed while the engine is stopped, and then insert electrical leak detector probe into drain
hose and hold for 10 minutes or more.

• When disconnecting shut-off valve that is connected to A/C service valve, always evacuate remaining

refrigerant so that misidentification can be avoided.

5.

Repair or replace parts where refrigerant leakage is detected. (Leakage is detected but leakage area is
unknown. GO TO 6.)

6.

Start the engine and set A/C control in the following conditions.
• A/C switch ON
• Air flow: VENT (ventilation)
• Intake door position: Recirculation

HA-20

< BASIC INSPECTION >

REFRIGERANT

• Temperature setting: Full cold
• Fan speed: Maximum speed set

7.

Run the engine at approximately 1,500 rpm for 2 minutes or more.

8.

Stop the engine. Check again for refrigerant leakage. GO TO 4.

WARNING:

Be careful not to get burned when the engine is hot.
NOTE:
• Start refrigerant leakage check immediately after the engine is

stopped.

• When refrigerant circulation is stopped, pressure on the low-

pressure side rises gradually, and after this, pressure on the
high-pressure side falls gradually.

• The higher the pressure is, the easier it is to find the refriger-

ant leakage.

Recycle Refrigerant

INFOID:0000000006276151

WARNING:

• Always use HFC-134a for A/C refrigerant. If CFC-12 is accidentally charged, compressor is damaged

due to insufficient lubrication.

• Always observe and follow precautions described on refrigerant container. Incorrect handling may

result in an explosion of refrigerant container, frostbite, or the loss of eyesight.

• Never breathe A/C refrigerant and lubricant vapor or mist. Exposure may irritate eyes, nose, or

throat.

• Never allow HFC-134a to be exposed to an open flame or others because it generates poisonous gas

when in contact with high temperature objects. Keep workshop well ventilated.

1.

Perform lubricant return operation. Refer to 

HA-22, "Perform Lubricant Return Operation"

. (If refrigerant or

lubricant leakage is detected in a large amount, omit this step, and then GO TO 2.)

CAUTION:

Never perform lubricant return operation if a large amount of refrigerant or lubricant leakage is
detected.

2.

Check gauge pressure readings of recovery/recycling/recharging equipment. When remaining pressure
exists, recycle refrigerant from high-pressure hose and low-pressure hose.
NOTE:
Follow manufacturer instructions for the handling or maintenance of the equipment. Never fill the equip-
ment with non-specified refrigerant.

3.

Remove A/C service valve cap from the vehicle.

4.

Connect recovery/recycling/recharging equipment to A/C service valve.

5.

Operate recovery/recycling/recharging equipment, and recycle refrigerant from the vehicle.

6.

Evacuate air for 10 minutes or more to remove any remaining refrigerant integrated to compressor lubri-
cant, etc.

7.

Refrigerant recycle operation is complete.

Charge Refrigerant

INFOID:0000000006276152

WARNING:

• Always use HFC-134a for A/C refrigerant. If CFC-12 is accidentally charged, compressor is damaged

due to insufficient lubrication.

• Always observe and follow precautions described on refrigerant container. Incorrect handling may

result in an explosion of refrigerant container, frostbite, or the loss of eyesight.

• Never breathe A/C refrigerant and lubricant vapor or mist. Exposure my irritate eyes, nose, or throat.
• Never allow HFC-134a to be exposed to an open flame or others because it generates poisonous gas

when in contact with high temperature objects. Keep workshop well ventilated.

1.

Connect recovery/recycling/recharging equipment to the A/C service valve.

SHA839E