Infiniti QX56 (Z62). Manual - part 810

REAR BLOWER MOTOR

HAC-131

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONING]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

REAR BLOWER MOTOR

Diagnosis Procedure

INFOID:0000000006275978

1.

CHECK FUSE

1.

Turn ignition switch OFF.

2.

Check 20A fuse [No. 16, located in fuse block (J/B)]. 
NOTE:
Refer to 

PG-140, "Fuse, Connector and Terminal Arrangement"

. 

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Replace the blown fuse after repairing the affected circuit if a fuse is blown. 

2.

CHECK REAR BLOWER MOTOR POWER SUPPLY

1.

Turn ignition switch OFF.

2.

Disconnect rear blower motor connector.

3.

Turn ignition switch ON.

4.

Check voltage between rear blower motor harness connector and ground. 

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair harness or connector between rear blower motor and fuse block (J/B). 

3.

CHECK REAR BLOWER MOTOR GROUND CIRCUIT

1.

Turn ignition switch OFF.

2.

Check continuity between rear blower motor harness connector and ground. 

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Repair harness or connector. 

4.

CHECK REAR BLOWER MOTOR CONTROL SIGNAL CIRCUIT

1.

Disconnect A/C auto amp. connector. 

2.

Check continuity between rear blower motor harness connector and A/C auto amp. harness connector. 

Is the inspection result normal?

YES

>> GO TO 5.

NO

>> Repair harness or connector.

5.

CHECK REAR BLOWER MOTOR CONTROL SIGNAL

1.

Reconnect rear blower motor connector and A/C auto amp. connector. 

2.

Turn ignition switch ON.

3.

Operate MODE switch to set air outlet to VENT. 

+

−

Voltage

Rear blower motor

Connector

Terminal

M302

1

Ground

Battery voltage

Rear blower motor

—

Continuity

Connector

Terminal

M302

3

Ground

Existed

Rear blower motor

A/C auto amp.

Continuity

Connector

Terminal

Connector

Terminal

M302

2

M50

34

Existed

HAC-132

< DTC/CIRCUIT DIAGNOSIS >

[AUTOMATIC AIR CONDITIONING]

REAR BLOWER MOTOR

4.

Change fan speed from Lo to Hi, and check duty ratios between rear blower motor harness connector and
ground by using an oscilloscope. 
NOTE:
Calculate drive signal duty ratio as shown in the figure.
T2 = Approx. 1.6 ms

Is the inspection result normal?

YES

>> Replace rear blower motor. Refer to 

VTL-16, "REAR A/C UNIT ASSEMBLY : Removal and Instal-

lation"

.

NO

>> Replace A/C auto amp.. Refer to 

HAC-146, "Removal and Installation"

.

Component Inspection

INFOID:0000000006275979

1.

CHECK REAR BLOWER MOTOR-I

1.

Remove rear blower motor.

2.

Check that there is not any mixing foreign object in the rear blower motor. 

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Replace rear blower motor. Refer to 

VTL-16, "REAR A/C UNIT ASSEMBLY : Removal and Instal-

lation"

.

2.

CHECK REAR BLOWER MOTOR-II

Check that there is not breakage or damage in the rear blower motor. 

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Replace rear blower motor. Refer to 

VTL-16, "REAR A/C UNIT ASSEMBLY : Removal and Instal-

lation"

.

3.

CHECK REAR BLOWER MOTOR-III

Check that rear blower motor turns smoothly. 

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace rear blower motor. Refer to 

VTL-16, "REAR A/C UNIT ASSEMBLY : Removal and Instal-

lation"

.

Rear blower motor

Condition

Duty ratio

(Approx.)

Connector

Terminal

Fan speed (manual)

VENT mode

M272

2

1st

25 %

2nd

33 %

3rd

41 %

4th

51 %

5th

61 %

6th

69 %

7th

81 %

JPLIA1210GB

FRONT AUTOMATIC AIR CONDITIONING SYSTEM

HAC-133

< SYMPTOM DIAGNOSIS >

[AUTOMATIC AIR CONDITIONING]

C

D

E

F

G

H

J

K

L

M

A

B

HAC

N

O

P

SYMPTOM DIAGNOSIS

FRONT AUTOMATIC AIR CONDITIONING SYSTEM

Diagnosis Chart By Symptom

INFOID:0000000006275980

NOTE:
Perform the self-diagnoses with CONSULT-III before performing the symptom diagnosis. If DTC is detected,
perform the corresponding diagnosis.

Symptom

Corresponding malfunction part

Reference

• Front air conditioning 

system does not activate.

• Front air conditioning 

system cannot be con-
trolled.

• Operation status of front 

air conditioning system is 
not indicated on front dis-
play.

Fail-safe activates

Multi AV system

AV-199, "Symptom Table"

Fail-safe does not acti-
vate

• Power supply system of A/C auto 

amp.

• A/C auto amp.

HAC-110, "A/C AUTO AMP. : Diag-
nosis Procedure"

• Air outlet does not change (Except upper ventila-

tion).

• Front mode door motor does not operate normally.

• Circuit between front mode door 

motor and A/C auto amp. 

• Front mode door motor control link-

age

• Front mode door motor
• A/C auto amp.

HAC-112, "FRONT MODE DOOR 
MOTOR : Diagnosis Procedure"

• Upper ventilator door does not change.
• Upper ventilator door motor does not operate nor-

mally.

• Circuit between upper ventilator 

door motor and A/C auto amp. 

• Upper ventilator door motor installa-

tion condition

• Upper ventilator door motor
• A/C auto amp.

HAC-116, "UPPER VENTILATOR 
DOOR MOTOR : Diagnosis Proce-
dure"

• Discharge air temperature of driver side does not 

change.

• Front air mix door motor (driver side) does not op-

erate normally.

• Circuit between front air mix door 

motor (driver side) and A/C auto 
amp. 

• Front air mix door motor (driver side) 

installation condition

• Front air mix door motor (driver side)
• A/C auto amp.

HAC-110, "FRONT AIR MIX DOOR 
MOTOR (DRIVER SIDE) : Diagno-
sis Procedure"

• Discharge air temperature of passenger side does 

not change.

• Front air mix door motor (passenger side) does not 

operate normally.

• Circuit between front air mix door 

motor (passenger side) and A/C 
auto amp. 

• Front air mix door motor (passenger 

side) installation condition

• Front air mix door motor (passenger 

side)

• A/C auto amp.

HAC-111, "FRONT AIR MIX DOOR 
MOTOR (PASSENGER SIDE) : Di-
agnosis Procedure"

• Intake door does not change.
• Intake door motor does not operate normally.

• Circuit between intake door motor 

and A/C auto amp. 

• Intake door motor control linkage
• Intake door motor
• A/C auto amp.

HAC-113, "INTAKE DOOR MOTOR 
: Diagnosis Procedure"

All door motors do not operate normally.

• Each door motor power supply and 

ground circuit

• A/C auto amp.

HAC-118, "Diagnosis Procedure"

Front blower motor operation is malfunctioning.

• Power supply system of front blower 

motor

• Circuit between front blower motor 

and A/C auto amp..

• Front blower motor
• A/C auto amp.

HAC-121, "Diagnosis Procedure"

HAC-134

< SYMPTOM DIAGNOSIS >

[AUTOMATIC AIR CONDITIONING]

FRONT AUTOMATIC AIR CONDITIONING SYSTEM

Compressor does not operate.

• Circuit between magnet clutch and 

IPDM E/R

• Magnet clutch
• IPDM E/R (A/C relay)
• Circuit between ECM and refriger-

ant pressure sensor

• Refrigerant pressure sensor
• CAN communication circuit
• A/C auto amp.

HAC-142, "Diagnosis Procedure"

• Insufficient cooling.
• No cool air comes out. (Air flow volume is normal.)

• Magnet clutch control system
• Drive belt slipping
• Refrigerant cycle
• Air leakage from each duct
• A/C auto amp. connection recogni-

tion signal circuit

• Temperature setting trimmer (front)

HAC-138, "FRONT AIR CONDI-
TIONER : Diagnosis Procedure"

• Insufficient heating.
• No warm air comes out. (Air flow volume is nor-

mal.)

• Engine cooling system
• Heater hose
• Heater core
• Air leakage from each duct
• Temperature setting trimmer (front)

HAC-140, "FRONT AIR CONDI-
TIONER : Diagnosis Procedure"

Noise is heard when front 
air conditioning system op-
erates.

During compressor 
operation

Refrigerant cycle

HA-27, "Symptom Table"

During front blower 
motor operation

• Mixing any foreign object in front 

blower motor

• Front blower motor fan breakage
• Front blower motor rotation inferiori-

ty

HAC-122, "Component Inspection 
(Front Blower Motor)"

• Memory function does not operate.
• Setting temperature is not memorized.

• Battery power supply system of A/C 

auto amp.

• A/C auto amp.

HAC-110, "A/C AUTO AMP. : Diag-
nosis Procedure"

Symptom

Corresponding malfunction part

Reference