Infiniti G37 Coupe. Manual - part 786

INSUFFICIENT HEATING

HAC-133

< SYMPTOM DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

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INSUFFICIENT HEATING

Description

INFOID:0000000001675743

Symptom

• Insufficient heating
• No warm air comes out. (Air flow volume is normal.)

Inspection procedure

INFOID:0000000001675744

1.

CHECK COOLING SYSTEM

1.

Check engine coolant level and check for leakage. Refer to 

CO-8, "Inspection"

.

2.

Check radiator cap. Refer to 

CO-12, "RADIATOR CAP : Inspection"

.

3.

Check water flow sounds of engine coolant. Refer to 

CO-9, "Refilling"

.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Refill the engine coolant and repair or replace the parts according to the inspection results.

2.

CHECK SETTING OF TEMPERATURE SETTING TRIMMER

1.

Check the setting of temperature setting trimmer. Refer to 

HAC-7, "WITHOUT LEFT AND RIGHT VENTI-

LATION TEMPERATURE SEPARATELY CONTROL SYSTEM : Temperature Setting Trimmer"

 (Without

left and right ventilation temperature separately control system) or 

HAC-11, "WITH LEFT AND RIGHT

VENTILATION TEMPERATURE SEPARATELY CONTROL SYSTEM : Temperature Setting Trimmer"

(With left and right ventilation temperature separately control system).

2.

Check that the temperature setting trimmer is set to “

−

 direction”. 

NOTE:
The control temperature can be set with the setting of temperature setting trimmer.

3.

Set temperature control dial to “0”.

Are the symptoms solved?

YES

>> Perform the setting separately if necessary. END.

NO

>> GO TO 3.

3.

CHECK OPERATION

1.

Turn temperature dial (driver side) and raise temperature setting to 32

°

C (90

°

F) after warming up the

engine.

2.

Check that warm air blows from outlets.

Is the inspection result normal?

YES

>> END.

NO

>> GO TO 4.

4.

PERFORM SELF-DIAGNOSIS STEP-2

Perform self-diagnosis STEP-2. Refer to 

HAC-42, "WITHOUT LEFT AND RIGHT VENTILATION TEMPERA-

TURE SEPARATELY CONTROL SYSTEM : Diagnosis Description"

 (Without left and right ventilation tempera-

ture separately control system) or 

HAC-48, "WITH LEFT AND RIGHT VENTILATION TEMPERATURE

SEPARATELY CONTROL SYSTEM : Diagnosis Description"

 (With left and right ventilation temperature sepa-

rately control system), see Nos. 1 to 2.

Does code No. 20 appear on the display?

YES

>> GO TO 5.

NO

>> Go to appropriate malfunctioning sensor circuit. Refer to 

HAC-42, "WITHOUT LEFT AND RIGHT

VENTILATION TEMPERATURE SEPARATELY CONTROL SYSTEM : Diagnosis Description"

(Without left and right ventilation temperature separately control system) or 

HAC-48, "WITH LEFT

AND RIGHT VENTILATION TEMPERATURE SEPARATELY CONTROL SYSTEM : Diagnosis
Description"

 (With left and right ventilation temperature separately control system), see No. 11.

5.

PERFORM SELF-DIAGNOSIS STEP-4

Perform self-diagnosis STEP-4. Refer to 

HAC-42, "WITHOUT LEFT AND RIGHT VENTILATION TEMPERA-

TURE SEPARATELY CONTROL SYSTEM : Diagnosis Description"

 (Without left and right ventilation tempera-

ture separately control system) or 

HAC-48, "WITH LEFT AND RIGHT VENTILATION TEMPERATURE

HAC-134

< SYMPTOM DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

INSUFFICIENT HEATING

SEPARATELY CONTROL SYSTEM : Diagnosis Description"

 (With left and right ventilation temperature sepa-

rately control system), see Nos. 1 to 5.
Is it installed normally?

YES

>> GO TO 6.

NO

>> Perform the diagnosis applicable to each output device. 

6.

PERFORM SELF-DIAGNOSIS STEP-5

Perform self-diagnosis STEP-5. Refer to 

HAC-42, "WITHOUT LEFT AND RIGHT VENTILATION TEMPERA-

TURE SEPARATELY CONTROL SYSTEM : Diagnosis Description"

 (Without left and right ventilation tempera-

ture separately control system) or 

HAC-48, "WITH LEFT AND RIGHT VENTILATION TEMPERATURE

SEPARATELY CONTROL SYSTEM : Diagnosis Description"

 (With left and right ventilation temperature sepa-

rately control system).
Is the inspection result normal?

YES

>> GO TO 7.

NO

>> Go to appropriate malfunctioning sensor circuit. Refer to 

HAC-42, "WITHOUT LEFT AND RIGHT

VENTILATION TEMPERATURE SEPARATELY CONTROL SYSTEM : Diagnosis Description"

(Without left and right ventilation temperature separately control system) or 

HAC-48, "WITH LEFT

AND RIGHT VENTILATION TEMPERATURE SEPARATELY CONTROL SYSTEM : Diagnosis
Description"

 (With left and right ventilation temperature separately control system).

7.

CHECK AIR LEAKAGE FROM DUCT

Check duct and nozzle, etc. of A/C system for air leakage.
Is the inspection result normal?

YES

>> GO TO 8.

NO

>> Repair or replace parts according to the inspection results.

8.

CHECK HEATER HOSE INSTALLATION CONDITION

Check the heater hose installation condition visually (for twist, crush, etc.).

Is the inspection result normal?

YES

>> GO TO 9.

NO

>> Repair or replace parts according to the inspection results.

9.

CHECK TEMPERATURE OF HEATER HOSE

1.

Check the temperature of inlet hose and outlet hose of heater core.

2.

Check that the inlet side of heater core is hot and the outlet side is slightly lower than/almost equal to the
inlet side.

CAUTION:

The temperature inspection should be performed in a short time because the engine coolant tem-
perature is too hot.

Is the inspection result normal?

YES

>> GO TO 10.

NO

>> Replace the heater core after performing the procedures after the cooling system inspection

again. GO TO 1.

10.

REPLACE HEATER CORE

Replace the heater core. Refer to heater core. Refer to 

VTL-42, "Exploded View"

.

Are the symptoms solved?

YES

>> END

NO

>> Perform the procedures after the cooling system inspection again. GO TO 1.

NOISE

HAC-135

< SYMPTOM DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

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NOISE

Description

INFOID:0000000001675745

Symptom

• Noise
• Noise is heard when the A/C system operates.

Inspection procedure

INFOID:0000000001675746

1.

CHECK OPERATION

1.

Operate the A/C system and check the operation. Refer to 

HAC-6, "WITHOUT LEFT AND RIGHT VENTI-

LATION TEMPERATURE SEPARATELY CONTROL SYSTEM : Description & Inspection"

 (Without left

and right ventilation temperature separately control system) or 

HAC-9, "WITH LEFT AND RIGHT VENTI-

LATION TEMPERATURE SEPARATELY CONTROL SYSTEM : Description & Inspection"

 (With left and

right ventilation temperature separately control system).

2.

Check the parts where noise is occurring.

Can the parts where noise is occurring be checked?

YES-1 >> Noise from blower fan motor: GO TO 2.
YES-2 >> Noise from compressor: GO TO 3.
YES-3 >> Noise from expansion valve: GO TO 4.
YES-4 >> Noise from A/C piping (pipe, flexible hose): GO TO 6.
YES-5 >> Noise from A/C compressor belt: GO TO 7.
NO

>> END.

2.

CHECK BLOWER MOTOR

1.

Remove blower motor.

2.

Remove in-cabin microfilter.

3.

Remove foreign materials that are in the blower unit.

4.

Check the noise from blower motor again.

Is the inspection result normal?

YES

>> END.

NO

>> Replace blower motor.

3.

REPLACE COMPRESSOR

1.

Correct the refrigerant with refrigerant recovery/recycling recharging equipment.

2.

Recharge with the proper amount of the collected refrigerant after recycling or new refrigerant.

3.

Check for the noise from compressor again.

Is the inspection result normal?

YES

>> END.

NO

>> Replace compressor.

4.

CHECK WITH GAUGE PRESSURE

Perform the diagnosis with the gauge pressure. Refer to 

HA-7, "Trouble Diagnosis For Unusual Pressure"

.

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Repair or replace malfunctioning part(s).

5.

REPLACE EXPANSION VALVE

1.

Correct the refrigerant with refrigerant recovery/recycling recharging equipment.

2.

Recharge with the proper amount of the collected refrigerant after recycling or new refrigerant.

3.

Check for the noise from expansion valve again.

Are the symptoms solved?

YES

>> END.

NO

>> Replace expansion valve.

6.

CHECK A/C PIPING (PIPE, FLEXIBLE HOSE)

HAC-136

< SYMPTOM DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

NOISE

1.

Check A/C piping (pipe, flexible hose) (for deformation and damage, etc.).

2.

Check the installation condition of clips and brackets, etc. of A/C piping (pipe, flexible hose).

Is the inspection result normal?

YES

>> Fix the line with rubber or come vibration absorbing material.

NO

>> Repair or replace parts according to the inspection results.

7.

CHECK DRIVE BELT

Check tension of the drive belt. Refer to 

EM-12, "Checking"

.

Is the inspection result normal?

YES

>> Check the noise from compressor: GO TO 3.

NO

>> Adjust or replace the drive belt according to the inspection results.