INFINITI M35 2007 Factory Service Manual
Page 531 of 4647
ATC-80
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
SYSTEM DESCRIPTION
Component Parts
Upper ventilator door control system components are:
Unified meter and A/C amp.
Upper ventilator door motor (LCU)
A/C LAN system (PBR built-in mode door motor, upper ventilator door motor, air mix door motor and
intake door motor)
Sunload 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, upper ventilator door and intake door opening angle data to the air mix door
motor LCUs, mode door motor LCUs, upper ventilator door motor LCU and intake door motor LCU.
The air mix door motors, mode door motors, upper ventilator 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, OPEN/SHUT and FRE/
REC operation is selected. The new selection data are returned to the unified meter and A/C amp.
RJIA4060E
Page 532 of 4647
TROUBLE DIAGNOSIS
ATC-81
C
D
E
F
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MA
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AT C
Revision: 2007 April2007 M35/M45
Upper Ventilator Door Control Specification
COMPONENT DESCRIPTION
Upper Ventilator Door Motor
The upper ventilator door motor is attached to the heater & cooling
unit assembly. It rotates so that air is discharged from the outlet set
by the unified meter and A/C amp. Motor rotation is conveyed to a
rod which activates the upper ventilator door.
DIAGNOSIS PROCEDURE FOR UPPER VENTILATOR DOOR MOTOR
SYMPTOM: Upper ventilator door motor does not operate normally.
Perform diagnosis procedure. Refer to AT C - 7 1 , "
DIAGNOSIS PROCEDURE FOR LAN CIRCUIT" .
RJIA4061E
RJIA4062E
Page 533 of 4647
ATC-82
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
Air Mix Door Motor CircuitNJS000GQ
SYMPTOM
Discharge air temperature does not change.
Air mix door motor does not operate normally.
INSPECTION FLOW
*1ATC-57, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 2 to 6.*2ATC-112, "
Ambient Sensor Circuit"*3ATC-115, "In-vehicle Sensor Circuit"
*4ATC-118, "Sunload Sensor Circuit"*5ATC-82, "Air Mix Door Motor Circuit"*6ATC-57, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13.
*7ATC-71, "
LAN System Circuit"*8ATC-65, "Operational Check"*9ATC-41, "SYMPTOM TABLE"
*10ATC-121, "Intake Sensor Circuit"
SJIA1762E
Page 534 of 4647
TROUBLE DIAGNOSIS
ATC-83
C
D
E
F
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K
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MA
B
AT C
Revision: 2007 April2007 M35/M45
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, upper ventilator door motor, air mix door motor and
intake door motor)
In-vehicle sensor
Ambient sensor
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, upper ventilator door and intake door opening angle data to the air mix door
motor LCUs, mode door motor LCUs, upper ventilator door motor LCU and intake door motor LCU.
The air mix door motors, mode door motors, upper ventilator 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, OPEN/SHUT 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
RJIA4217E
RJIA1782E
Page 535 of 4647
ATC-84
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
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.
DIAGNOSIS PROCEDURE FOR AIR MIX DOOR MOTOR
SYMPTOM: Discharge air temperature does not change.
Perform diagnosis procedure. Refer to AT C - 7 1 , "
DIAGNOSIS PROCEDURE FOR LAN CIRCUIT" .
Air Mix Door Motor PBR CircuitNJS000GR
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 AT C - 7 1 , "DIAGNOSIS PROCEDURE FOR LAN CIRCUIT" .
RJIA4064E
RJIA4065E
Page 536 of 4647
TROUBLE DIAGNOSIS
ATC-85
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AT C
Revision: 2007 April2007 M35/M45
Intake Door Motor CircuitNJS000GS
SYMPTOM
Intake door does not change.
Intake door motor does not operate normally.
INSPECTION FLOW
*1ATC-57, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 2 to 6.*2AT C - 11 2 , "
Ambient Sensor Circuit"*3ATC-115, "In-vehicle Sensor Circuit"
*4ATC-118, "Sunload Sensor Circuit"*5AT C - 8 2 , "Air Mix Door Motor Cir-
cuit"
*6ATC-57, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13.
*7ATC-71, "
LAN System Circuit"*8ATC-132, "INTAKE DOOR
MOTOR"
*9ATC-65, "Operational Check"
*10ATC-41, "SYMPTOM TABLE"*11ATC-121, "Intake Sensor Circuit"
RJIA4066E
Page 537 of 4647
ATC-86
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
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, upper ventilator door motor, air mix door motor and
intake door motor)
In-vehicle sensor
Ambient sensor
Sunload sensor
Intake sensor
System Operation
The intake door control determines intake door position based on the ambient temperature, the intake air tem-
perature and the in-vehicle temperature. When shifting mode position D/F, when the DEF or OFF switches are
pressed, or when A/C switch is OFF, the unified meter and A/C amp. sets the intake door at the FRE position.
Intake Door Control Specification
RJIA4214E
RJIA4067E
Page 538 of 4647
TROUBLE DIAGNOSIS
ATC-87
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AT C
Revision: 2007 April2007 M35/M45
COMPONENT DESCRIPTION
Intake Door Motor
The intake door motor is attached to the blower unit. It rotates so that
air is drawn from inlets set by the unified meter and A/C amp. Motor
rotation is conveyed to a lever which activates the intake door.
DIAGNOSIS PROCEDURE FOR INTAKE DOOR MOTOR
SYMPTOM: Intake door motor does not operate normally.
Perform diagnosis procedure. Refer to AT C - 7 1 , "
DIAGNOSIS PROCEDURE FOR LAN CIRCUIT" .
RJIA4068E
Page 539 of 4647
ATC-88
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
Blower Motor CircuitNJS000GT
SYMPTOM: Blower motor operation is malfunctioning.
INSPECTION FLOW
*1AT C - 6 5 , "Operational Check"*2ATC-121, "Intake Sensor Circuit"*3AT C - 5 7 , "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 2.
*4AT C - 5 7 , "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 6.*5ATC-57, "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13.*6AT C - 9 0 , "
DIAGNOSIS PROCE-
DURE FOR BLOWER MOTOR"
*7AT C - 4 1 , "SYMPTOM TABLE"*8ATC-112, "Ambient Sensor Circuit"*9AT C - 11 5 , "In-vehicle Sensor Circuit"
*10AT C - 11 8 , "Sunload Sensor Circuit"*11EC-214, "DTC P0117, P0118 ECT
SENSOR" (VQ35DE) or EC-926,
"DTC P0117, P0118 ECT SEN-
SOR" (VK45DE)
RJIA4069E
Page 540 of 4647
TROUBLE DIAGNOSIS
ATC-89
C
D
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MA
B
AT C
Revision: 2007 April2007 M35/M45
SYSTEM DESCRIPTION
Component Parts
Fan speed control system components are:
Unified meter and A/C amp.
A/C LAN system (PBR built-in mode door motor, upper ventilator door motor, air mix door motor and
intake door motor)
In-vehicle sensor
Ambient sensor
Sunload sensor
Intake sensor
System Operation
Automatic Mode
In the automatic mode, the blower motor speed is calculated by the unified meter and A/C amp. based on the
input from the PBR, in-vehicle sensor, sunload sensor, intake sensor and ambient sensor.
When the air flow is increased, the duty ratio of the blower fan motor’s drive signal is changed at 8%/sec. to
prevent a sudden increase in air flow.
In addition to manual air flow control and the usual automatic air flow control, starting air flow control, low
water temperature starting control and high passenger compartment temperature starting control are avail-
able.
RJIA4070E