Infiniti G37 Coupe. Manual - part 766

DIAGNOSIS SYSTEM (AUTO AMP.)

HAC-53

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

When performing indoors, aim a light (more than 60 W) at sunload sensor, otherwise code No. 25 indicates
despite that sunload sensor is functioning normally.

>> INSPECTION END

12.

CHECK MALFUNCTIONING DOOR MOTOR POSITION SWITCH

Mode and/or intake door motor PBR(s) is/are malfunctioning.

(Corresponding code Nos. indicates 1 second each if two or more mode or intake door motors malfunction.)
*1: The following display pattern will appear if mode door motor harness connector is disconnected.
31

→

32

→

Return to 31

*2: The following display pattern will appear if intake door motor harness connector is disconnected.
37

→

38

→

39

→

Return to 37

>> INSPECTION END

WITH LEFT AND RIGHT VENTILATION TEMPERATURE SEPARATELY CONTROL 
SYSTEM : CONSULT-III Function

INFOID:0000000001713980

CONSULT-III APPLICATION ITEMS

CONSULT-III can display each diagnosis item using the diagnosis test modes shown as per the following.

DATA MONITOR

SJIA1781E

Code No. 

*1 *2

Mode or intake door position

Reference

31

VENT

Mode door motor

HAC-67, "Diagnosis Procedure"

32

DEF

37

FRE

Intake door motor

HAC-75, "Diagnosis Procedure"

38

20% FRE

39

REC

SJIA1782E

System part

Check item, diagnosis mode

Description

ECM

Data monitor

Displays ECM input data in real time.

HAC-54

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

DIAGNOSIS SYSTEM (AUTO AMP.)

Display Item List

Monitor Item

Condition

Value/Status

IGN ON SW

Ignition switch OFF 

→

 ON

OFF 

→

 ON

FAN ON SIG

Ignition switch ON

Blower fan motor switch ON

ON

Blower fan motor switch OFF

OFF

AIR COND SW

Ignition switch ON

Compressor ON

ON

Compressor OFF

OFF

REFRIGERANT PRESSURE 
SENSOR

• Engine is running
• Warm-up condition
• Both A/C switch and blower fan motor switch: ON (Compressor 

operates)

1.0 - 4.0 V

MODE DOOR CONTROL SYSTEM

HAC-55

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

MODE DOOR CONTROL SYSTEM

System Diagram

INFOID:0000000001733793

System Description

INFOID:0000000001733794

The mode door is automatically controlled by the temperature setting, ambient temperature, in-vehicle temper-
ature, intake temperature and amount of sunload.

SYSTEM OPERATION

• The unified meter and A/C amp. receives data from each of the sensors.
• The unified meter and A/C amp. sends air mix door, mode door and intake door opening angle data to the air

mix door motor LCU(s), mode door motor LCU and intake door motor LCU.

• The air mix door motor(s), mode door motor and intake door motor read their respective signals according to

the address signal. Opening angle indication signals received from the unified meter and A/C amp. and each
of the motor position sensors are compared by the LCUs in each door motor with the existing decision and
opening angles.

• Subsequently, HOT/COLD, DEF/VENT and FRE/REC operation is selected. The new selection data are

returned to the unified meter and A/C amp.

Door Motor Circuit

Mode Door Control Specification

JSIIA0772GB

JSIIA0773GB

HAC-56

< FUNCTION DIAGNOSIS >

[AUTOMATIC AIR CONDITIONER]

MODE DOOR CONTROL SYSTEM

Mode position can be selected manually by pressing MODE switch
or DEF switch of the preset switch. This enables to fix a mode posi-
tion. Automatic control by unified meter and A/C amp. Pressing
AUTO switch allows automatic control by unified meter and A/C
amp. During the automatic control of mode position, a mode door
position (VENT, B/L, FOOT, or D/F) is selected based on a target air
mix door opening angle and sunload depending on a temperature
calculated by unified meter and A/C amp. In addition, D/F is selected
to prevent windshield fogging only when ambient temperature is
extremely low with mode position FOOT.

RJIA1778E