2005 INFINITI FX35 turn signal

ATC-30
AIR CONDITIONER CONTROL
Revision: 2005 July 2005 FX
AIR CONDITIONER CONTROLPFP:27500
Description of Air Conditioner LAN Control SystemAJS0014A
The LAN (Local Area Network) system consists of unified meter and A/C amp., mode door motor, air mix door
motor and intake door motor.
A configuration of these components is shown in the diagram below.
System ConstructionAJS0014B
A small network is constructed between the unified meter and A/C amp., air mix door motor, mode door motor
and intake door motor. The unified meter and A/C amp. and motors are connected by data transmission lines
and motor power supply lines. The LAN network is built through the ground circuits of each door motor.
Addresses, motor opening angle signals, motor stop signals and error checking messages are all transmitted
through the data transmission lines connecting the unified meter and A/C amp. and each door motor.
The following functions are contained in LCUs built into the air mix door motor, the mode door motor and the
intake door motor.

Address

Motor opening angle signals

Data transmission

Motor stop and drive decision

Opening angle sensor (PBR function)

Comparison

Decision (Unified meter and A/C amp. indicated value and motor opening angle comparison)
OPERATION
The unified meter and A/C amp. receives data from each of the sensors. The unified meter and A/C amp.
sends mode door, air mix door and intake door opening angle data to the mode door motor LCU, air mix door
motor LCU and intake door motor LCU.
The mode door motor, air mix 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 is compared by the LCUs in each motor with the existing decision and opening
angles. Subsequently, HOT/COLD, DEF/VENT and FRESH/RECIRCULATION operation is selected. The new
selection data is returned to the unified meter and A/C amp.
SJIA0262E
RJIA1747E

AIR CONDITIONER CONTROL ATC-33
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MAGNET CLUTCH CONTROL
When A/C switch or DEF switch is pressed, unified meter and A/C amp. inputs compressor ON signal to BCM.
BCM sends compressor ON signal to ECM, via CAN communication line.
ECM judges whether compressor can be turned ON, based on each sensor status (refrigerant-pressure sen-
sor signal, throttle angle, etc.). If it judges compressor can be turned ON, it sends compressor ON signal to
IPDM E/R, via CAN communication line.
Upon receipt of compressor ON signal from ECM, IPDM E/R turns air conditioner relay ON to operate com-
pressor.
When sending compressor ON signal to IPDM E/R via CAN communication line, ECM simultaneously sends
compressor feedback signal to unified meter and A/C amp. via CAN communication line.
Unified meter and A/C amp., then, uses input compressor feedback signal to control air inlet.
SELF-DIAGNOSIS SYSTEM
The self-diagnosis system is built into the unified meter and A/C amp. to quickly locate the cause of symp-
toms.
RJIA1957E

ATC-66
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
LAN System CircuitAJS0014S
SYMPTOM: Mode door motor, intake door motor and/or air mix door motor(s) does not operate normally.
DIAGNOSIS PROCEDURE FOR LAN CIRCUIT
1. CHECK POWER SUPPLY FOR UNIFIED METER AND A/C AMP.
1. Turn ignition switch ON.
2. Check voltage between unified meter and A/C amp. harness connector M57 terminal 54 (Y/R) and ground.
OK or NG
OK >> GO TO 2.
NG >> Replace unified meter and A/C amp.
2. CHECK SIGNAL FOR UNIFIED METER AND A/C AMP.
Confirm A/C LAN signal between unified meter and A/C amp. har-
ness connector M57 terminal 43 (G/B) and ground using an oscillo-
scope.
OK or NG
OK >> GO TO 3.
NG >> Replace unified meter and A/C amp.
RJIA1775E
54 – Ground : Battery voltage
RJIA1986E
Terminals
Voltage
(+)
( − )
Unified meter and A/
C amp. connector Terminal No.
(wire color)
M57 43 (G/B) Ground
RJIA1987E
HAK0652D

TROUBLE DIAGNOSIS ATC-67
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3. CHECK POWER SUPPLY FOR EACH DOOR MOTOR
Check voltage between each door motor harness connector terminal
1 and ground.
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4. CHECK SIGNAL FOR EACH DOOR MOTOR
Confirm A/C LAN signal between each door motor harness connec-
tor terminal 3 and ground using an oscilloscope.
OK or NG
OK >> GO TO 5.
NG >> Repair harness or connector.
5. CHECK MOTOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect each door motor connector.
3. Check continuity between each door motor harness connector terminal 2 and ground.
OK or NG
OK >> GO TO 6.
NG >> Repair harness or connector. 1 – Ground : Battery voltage
RJIA1988E
Door motor
Terminals
Voltage
(+)
( − )
Con-
nector Terminal
No.
(wire color)
Mode M258 3 (L)
Ground
Air mix
(Driver
side) M252 3 (L)
Air mix
(Passen-
ger side) M257 3 (L)
Intake M253 3 (L)
RJIA1989E
HAK0652D
2 – Ground : Continuity should exist.
RJIA1990E

TROUBLE DIAGNOSIS ATC-71
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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 door motor with the existing decision and open-
ing angles. Subsequently, HOT/COLD, DEF/VENT and FRESH/RECIRCULATION operation is selected. The
new selection data are returned to the unified meter and A/C amp.
RJIA1777E

ATC-74
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
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 motor 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 door motor with the existing decision and open-
ing angles. Subsequently, HOT/COLD, DEF/VENT and FRESH/RECIRCULATION operation is selected. The
new selection data are returned to the unified meter and A/C amp.
Air Mix Door Control Specification
RJIA1781E
RJIA1782E

TROUBLE DIAGNOSIS ATC-83
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4. CHECK UNIFIED METER AND A/C AMP. OUTPUT SIGNAL
1. Reconnect blower motor connector and unified meter and A/C amp. connector.
2. Turn ignition switch ON.
3. Change the fan speed from Lo to Hi, and check the duty ratios between blower motor harness connector M78 terminal 2 (G) and ground using an oscilloscope. Normal terminal 2 (G) drive signal duty ratios are
shown in the table below.
OK or NG
OK >> Replace blower motor after confirming the fan air flow does not change.
NG >> Replace unified meter and A/C amp.
COMPONENT INSPECTION
Blower Motor
Confirm smooth rotation of the blower motor.

Ensure that there are no foreign particles inside the blower unit.
RJIA2000E
RJIA2001E
RJIA0905E

TROUBLE DIAGNOSIS ATC-85
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Revision: 2005 July 2005 FX
SYSTEM DESCRIPTION
Unified meter and A/C amp. controls compressor operation by ambient temperature, intake air temperature
and signal from ECM.
Low Temperature Protection Control
Unified meter and A/C amp. will turn the compressor ON or OFF as determined by a signal detected by ambi-
ent sensor and intake sensor.
When ambient temperature is higher than −2 °C (28 °F), the compres-
sor turns ON. The compressor turns OFF when ambient temperature
is lower than −5 °C (23 °F).
When intake air temperature is higher than 1 °C (34 °F), the compres-
sor turns ON. The compressor turns OFF when intake air tempera-
ture is lower than −5°C (23 °F).
DIAGNOSIS PROCEDURE FOR MAGNET CLUTCH
SYMPTOM: Magnet clutch does not engage when A/C switch is ON.
RHA094GB
SJIA0267E
RJIA2003E