Infiniti FX35 / FX45. Manual - part 116

ATC-60

< SERVICE INFORMATION >

TROUBLE DIAGNOSIS

SYSTEM DESCRIPTION

Component Parts

Air mix door control system components are:

• Unified meter and A/C amp.
• Air mix door motor (LCU)
• A/C LAN system (PBR built-in mode door motor, air mix door motor and intake door motor)
• In-vehicle sensor
• Ambient sensor

*1

ATC-43, "Self-Diagnosis Function"

, 

see No. 4 to 6.

*2

ATC-86, "Ambient Sensor Circuit"

*3

ATC-88, "In-vehicle Sensor Circuit"

*4

ATC-91, "Sunload Sensor Circuit"

*5

ATC-62, "Air Mix Door Motor PBR 
Circuit"

*6

ATC-43, "Self-Diagnosis Function"

, 

see No. 13.

*7

ATC-54, "LAN System Circuit"

.

*8

ATC-50, "Operational Check"

*9

ATC-32, "How to Perform Trouble 
Diagnosis for Quick and Accurate 
Repair"

*10

ATC-94, "Intake Sensor Circuit"

SJIA1586E

TROUBLE DIAGNOSIS

ATC-61

< SERVICE INFORMATION >

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• Sunload sensor
• Intake sensor

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 motor opening angle data to the air mix door motor LCUs,
mode door motor LCU and intake door motor LCU.
The air mix door motors, 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 open-
ing 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.

Air Mix Door Control Specification

COMPONENT DESCRIPTION

Air Mix Door Motor

The air mix door motors are attached to the heater & cooling unit
assembly. It rotates so that the air mix door is opened or closed to a
position set by the unified meter and A/C amp. Motor rotation is then
conveyed through a shaft and the air mix door position feedback is
then sent to the unified meter and A/C amp. by PBR built-in air mix
door motor.

RJIA1781E

RJIA1782E

RJIA0893E

ATC-62

< SERVICE INFORMATION >

TROUBLE DIAGNOSIS

DIAGNOSIS PROCEDURE FOR AIR MIX DOOR MOTOR

SYMPTOM: Discharge air temperature does not change.
Perform diagnosis procedure. Refer to 

ATC-54, "LAN System Circuit"

.

Air Mix Door Motor PBR Circuit

INFOID:0000000001328187

SYMPTOM

• Discharge air temperature does not change.
• PBR circuit is open or shorted.

DIAGNOSIS PROCEDURE FOR AIR MIX DOOR MOTOR PBR

Perform diagnosis procedure. Refer to 

ATC-54, "LAN System Circuit"

. 

Intake Door Motor Circuit

INFOID:0000000001328188

SYMPTOM

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

INSPECTION FLOW

RJIA0894E

TROUBLE DIAGNOSIS

ATC-63

< SERVICE INFORMATION >

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ATC

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SYSTEM DESCRIPTION

Component Parts

Intake door control system components are:

• Unified meter and A/C amp.
• Intake door motor (LCU)
• A/C LAN system (PBR built-in mode door motor, air mix door motor and intake door motor)
• In-vehicle sensor
• Ambient sensor
• Sunload sensor

*1

ATC-50, "Operational Check"

*2

ATC-43, "Self-Diagnosis Function"

, 

see No. 4 to 6.

*3

ATC-86, "Ambient Sensor Circuit"

*4

ATC-88, "In-vehicle Sensor Circuit"

*5

ATC-91, "Sunload Sensor Circuit"

*6

ATC-94, "Intake Sensor Circuit"

*7

ATC-59, "Air Mix Door Motor Circuit"

*8

ATC-32, "How to Perform Trouble 
Diagnosis for Quick and Accurate 
Repair"

*9

ATC-43, "Self-Diagnosis Function"

, 

see No. 13.

*10

ATC-54, "LAN System Circuit"

*11

ATC-106

SJIA1807E