Page 483 of 4647

ATC-32
AIR CONDITIONER CONTROL
Revision: 2007 April2007 M35/M45
MAGNET CLUTCH CONTROL
When A/C switch, AUTO switch or DEF switch is pressed, unified meter and A/C amp. transmits compressor
ON signal to ECM, via CAN communication.
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.
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 ECM via CAN communication line.
ECM sends compressor feedback signal to unified meter and A/C amp., then, uses input compressor feed-
back 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 malfunc-
tions.
RJIA4020E
Page 522 of 4647
TROUBLE DIAGNOSIS
ATC-71
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: 2007 April2007 M35/M45
LAN System CircuitNJS000GN
SYMPTOM: Mode door motors, upper ventilator door motor, air mix door motors and intake door motor 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 M65 terminal 70 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 M65 terminal 69 and ground using an oscilloscope.
OK or NG
OK >> GO TO 3.
NG >> Replace unified meter and A/C amp.
RJIA4052E
70 – Ground : Battery voltage
RJIA4053E
Terminals
Vo l ta g e (+)
(−)
Unified meter and
A/C amp. connectorTerminal No.
M65 69 Ground
RJIA4054E
SJIA1453J
Page 523 of 4647

ATC-72
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
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 motorTerminals
Vo l ta g e (+)
(−)
Con-
nectorTerminal
No.
Mode (Driver
side)M252 3
Ground Mode (Pas-
senger side)M255 3
Upper venti-
latorM254 3
Air mix
(Driver side)M253 3
Air mix (Pas-
senger side)M256 3
Intake M257 3
RJIA1989E
SJIA1453J
2 – Ground : Continuity should exist.
RJIA1990E
Page 528 of 4647

TROUBLE DIAGNOSIS
ATC-77
C
D
E
F
G
H
I
K
L
MA
B
AT C
Revision: 2007 April2007 M35/M45
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, 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.
*1ATC-37, "Discharge Air Flow"*2AT C - 6 5 , "Operational Check"*3ATC-121, "Intake Sensor Circuit"
*4ATC-57, "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 2 to 6.*5AT C - 11 2 , "
Ambient Sensor Circuit"*6AT C - 11 5 , "In-vehicle Sensor Circuit"
*7ATC-118, "Sunload Sensor Circuit"*8AT C - 8 2 , "Air Mix Door Motor Cir-
cuit"
*9AT C - 5 7 , "FUNCTION CONFIRMA-
TION PROCEDURE", see No. 13.
*10ATC-71, "
DIAGNOSIS PROCE-
DURE FOR LAN CIRCUIT"
*11ATC-139, "MODE DOOR MOTOR"*12AT C - 4 1 , "SYMPTOM TABLE"
RJIA4056E
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 534 of 4647

TROUBLE DIAGNOSIS
ATC-83
C
D
E
F
G
H
I
K
L
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 543 of 4647
ATC-92
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
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. Set MODE switch to VENT position.
4. Change the fan speed from Lo to Hi, and check the duty ratios
between blower motor harness connector M91 terminal 2 and
ground by using an oscilloscope. Normal terminal 2 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.
RJIA4074E
RJIA4075E
RJIA4076E
Page 545 of 4647
ATC-94
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
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 compressor ON or OFF as determined by a signal detected by ambient
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
RJIA4078E