CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER]


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1.  Remove the climate control unit with the connector connected. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER].)

2.  Switch the ignition ON (engine off or on).

3.  Connect the negative (-) lead of the tester to body ground.

4.  By inserting the positive (+) lead of the tester into each climate control unit terminal, measure the voltage according to the terminal voltage table.

•  If there is any malfunction, inspect the parts under “Inspection item (s)”.
―  If the parts under “Inspection item (s)” are found to be normal (except for terminal Q), replace the climate control unit.
―  For terminal Q, first try replacing the blower fan controller. If there is still any malfunction, replace the climate control unit.


Terminal Voltage Table (Reference)

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Terminal

Signal name

Connected to

Measurement condition

Voltage (V)

Inspection item (s)

A
B
MS_CAN_L
CAN related module
Because this terminal is for communication, good/no good judgment by terminal voltage is not possible.
•  Related wiring harness
C
GND
Body ground
Under any condition
1.0 or less
•  Related wiring harness
D
MS_CAN_H
CAN related module
Because this terminal is for communication, good/no good judgment by terminal voltage is not possible.
•  Related wiring harness
E
Sensor GND
•  Air mix actuator
•  Airflow mode actuator
•  Evaporator temperature sensor
Under any condition
1.0 or less
•  Related wiring harness
•  Climate control unit: terminal voltage (G)
F
G
Potentiometer input
Air mix actuator
Set temperature at MAX HOT
4.3 or more
•  Related wiring harness
•  Air mix actuator
•  Climate control unit: terminal voltage (G)
Set temperature at MAX COLD
1.0 or less
H
+5V
•  Air mix actuator
•  Airflow mode actuator
Under any condition
5
•  Related wiring harness
•  Air mix actuator
•  Airflow mode actuator
•  Climate control unit: terminal voltage (K)
I
Potentiometer input
Airflow mode actuator
VENT
4.3 or more
•  Related wiring harness
•  Airflow mode actuator
•  Climate control unit: terminal voltage (G)
BI-LEVEL
3.4
HEAT
2.5
HEAT/DEF
1.6
DEFROSTER
0.7 or less
J
Evaporator temperature sensor input
Evaporator temperature sensor
Compared with temperature detected by evaporator temperature sensor
Refer to graph 1
•  Related wiring harness
•  Evaporator temperature sensor
•  Climate control unit: terminal voltage (G)
K
L
B+
ROOM 15 A fuse
Under any condition
B+
•  Related wiring harness
•  ROOM 15 A fuse
M
N
IG2
Front body control module (FBCM)
Switch the ignition ON (engine off or on)
B+
•  Related wiring harness
•  Front body control module (FBCM)
Switch the ignition off
1.0 or less
O
P
Q
Blower fan speed control
Blower fan controller
•  Related wiring harness
•  Blower fan controller
R
S
Motor operation (RECIRCULATE)
Air intake actuator
Moving towards RECIRCULATE
B+
•  Related wiring harness
•  Air intake actuator
Moving towards FRESH
1.0 or less
T
Motor operation (VENT)
Airflow mode actuator
Moving towards VENT
B+
•  Related wiring harness
•  Airflow mode actuator
Moving towards DEFROSTER
1.0 or less
U
Motor operation (FRESH)
Air intake actuator
Moving towards RECIRCULATE
1.0 or less
•  Related wiring harness
•  Air intake actuator
Moving towards FRESH
B+
V
Motor operation (DEFROSTER)
Airflow mode actuator
Moving towards DEFROSTER
B+
•  Related wiring harness
•  Airflow mode actuator
Moving towards VENT
1.0 or less
W
Motor operation (COLD)
Air mix actuator
Moving towards HOT
1.0 or less
•  Related wiring harness
•  Air mix actuator
Moving towards COLD
B+
X
Motor operation (HOT)
Air mix actuator
Moving towards HOT
B+
•  Related wiring harness
•  Air mix actuator
Moving towards COLD
1.0 or less


Blower Fan Speed Control Signal


Fan stopped

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Climate control unit terminal
•  Q(+)—body ground(-)
Oscilloscope setting
•  5 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
•  Switch the ignition ON (engine off or on)


Manual 1st

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Climate control unit terminal
•  Q(+)—body ground(-)
Oscilloscope setting
•  5 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
•  Switch the ignition ON (engine off or on)
•  Airflow mode: VENT
•  Air intake mode: RECIRCULATE


Manual 3rd

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Climate control unit terminal
•  Q(+)—body ground(-)
Oscilloscope setting
•  5 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
•  Switch the ignition ON (engine off or on)
•  Airflow mode: VENT
•  Air intake mode: RECIRCULATE


Manual 7th

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Climate control unit terminal
•  Q(+)—body ground(-)
Oscilloscope setting
•  5 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
•  Switch the ignition ON (engine off or on)
•  Airflow mode: VENT
•  Air intake mode: RECIRCULATE