2004 INFINITI FX35 sensor

TROUBLE DIAGNOSIS
ATC-71
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: 2004 November 2004 FX35/FX45
SYSTEM DESCRIPTION
Component Parts
Mode door control system components are:

Unified meter and A/C amp.

Mode 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

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 opening angle data to the air mix door motor LCU, mode door
motor LCU and intake door motor LCU.
The air mix door motor, 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 motor with the existing decision and opening
angles. Subsequently, HOT/COLD or DEFROST/VENT or FRESH/RECIRCULATION operation is selected.
The new selection data is returned to the unified meter and A/C amp.
RJIA1777E

TROUBLE DIAGNOSIS
ATC-73
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: 2004 November 2004 FX35/FX45
Air Mix Door Motor CircuitAJS0014U
SYMPTOM:

Discharge air temperature does not change.

Air mix door motor does not operate.
INSPECTION FLOW
*1ATC-54, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 4 to 6.*2ATC-104, "
Ambient Sensor Circuit".*3ATC-107, "In-vehicle Sensor Cir-
cuit".
*4ATC-110, "
Sunload Sensor Circuit"*5ATC-73, "Air Mix Door Motor Cir-
cuit".*6ATC-54, "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13.
*7ATC-66, "
LAN System Circuit".*8ATC-75, "COMPONENT DESCRIP-
TION".*9ATC-131, "
AIR MIX DOOR
MOTOR".
*10ATC-61, "
Operational Check".*11ATC-42, "SYMPTOM TABLE".*12ATC-113, "Intake Sensor Circuit".
RJIA1992E

ATC-74
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
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

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 opening angle data to the air mix door motor LCU, mode door
motor LCU and intake door motor LCU.
The air mix door motor, 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 motor with the existing decision and opening
angles. Subsequently, HOT/COLD or DEFROST/VENT or FRESH/RECIRCULATION operation is selected.
The new selection data is returned to the unified meter and A/C amp.
Air Mix Door Control Specification
RJIA1781E
RJIA1782E

ATC-76
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
Intake Door Motor CircuitAJS0014W
SYMPTOM:

Intake door does not change.

Intake door motor does not operate normally.
INSPECTION FLOW
*1AT C - 5 4 , "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 4 to 6.*2ATC-104, "
Ambient Sensor Circuit".*3ATC-107, "In-vehicle Sensor Circuit".
*4AT C - 11 0 , "
Sunload Sensor Circuit".*5AT C - 7 3 , "Air Mix Door Motor Cir-
cuit".*6AT C - 5 4 , "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13.
*7AT C - 6 6 , "
LAN System Circuit".*8ATC-124, "INTAKE DOOR
MOTOR".*9AT C - 6 1 , "
Operational Check".
*10AT C - 4 2 , "
SYMPTOM TABLE".*11AT C - 11 3 , "Intake Sensor Circuit".
RJIA1993E

TROUBLE DIAGNOSIS
ATC-77
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: 2004 November 2004 FX35/FX45
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

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 the DEFROST, or OFF switches are pushed or A/C switch is
OFF, the unified meter and A/C amp. sets the intake door at the FRESH position.
Intake Door Control Specification
RJIA1786E
RJIA1787E

TROUBLE DIAGNOSIS
ATC-79
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: 2004 November 2004 FX35/FX45
Blower Motor CircuitAJS0014X
SYMPTOM:

Blower motor operation is malfunctioning.

Blower motor operation is malfunctioning under out of starting fan speed control.
INSPECTION FLOW
*1ATC-61, "Operational Check".*2AT C - 11 3 , "Intake Sensor Circuit".*3ATC-54, "FUNCTION CONFIRMA-
TION PROCEDURE", see No.4.
*4ATC-54, "
FUNCTION CONFIRMA-
TION PROCEDURE", see No.6.*5AT C - 5 4 , "
FUNCTION CONFIRMA-
TION PROCEDURE", see No.13.*6ATC-81, "
DIAGNOSTIC PROCE-
DURE FOR BLOWER MOTOR".
RJIA1994E

ATC-80
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
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, 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
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.
*7AT C - 4 2 , "SYMPTOM TABLE".*8ATC-104, "Ambient Sensor Circuit".*9ATC-107, "In-vehicle Sensor Cir-
cuit".
*10AT C - 11 0 , "
Sunload Sensor Circuit".*11EC-185, "DTC P0117, P0118 ECT
SENSOR" (VQ35DE) or EC-842,
"DTC P0117, P0118 ECT SEN-
SOR" (VK45DE).
RJIA1995E

ATC-84
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
Magnet Clutch CircuitAJS0014Y
SYMPTOM: Magnet clutch does not engage.
INSPECTION FLOW
*1ATC-113, "Intake Sensor Circuit".*2ATC-104, "Ambient Sensor Circuit".*3AT C - 5 4 , "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13.
*4ATC-85, "
DIAGNOSTIC PROCE-
DURE FOR MAGNET CLUTCH".*5ATC-96, "
TROUBLE DIAGNOSIS
FOR UNUSUAL PRESSURE".*6AT C - 6 1 , "
Operational Check".
*7ATC-54, "
FUNCTION CONFIRMA-
TION PROCEDURE", see No. 4 to 6.*8ATC-42, "
SYMPTOM TABLE".
RJIA2002E