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 E), replace the climate control unit.

― For terminal E, 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

GND

Body ground

Under any condition

1.0 or less

•  Related wiring harness

B

B+

ROOM 15 A fuse

Under any condition

B+

•  Related wiring harness

•  ROOM 15 A fuse

C

—

—

—

—

—

D

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

E

Blower fan speed control

Blower fan controller

(See Blower Fan Speed Control Signal)

•  Related wiring harness

•  Blower fan controller

F

—

—

—

—

—

G

+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)

H

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)

I

—

—

—

—

—

J

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

K

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)

L

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

M

—

—

—

—

—

N

Motor operation (VENT)

Airflow mode actuator

Moving towards VENT

B+

•  Related wiring harness

•  Airflow mode actuator

Moving towards DEFROSTER

1.0 or less

O

—

—

—

—

—

P

Motor operation (DEFROSTER)

Airflow mode actuator

Moving towards DEFROSTER

B+

•  Related wiring harness

•  Airflow mode actuator

Moving towards VENT

1.0 or less

Q

—

—

—

—

—

R

Motor operation (FRESH)

Air intake actuator

Moving towards RECIRCULATE

1.0 or less

•  Related wiring harness

•  Air intake actuator

Moving towards FRESH

B+

S

—

—

—

—

—

T

Motor operation (RECIRCULATE)

Air intake actuator

Moving towards RECIRCULATE

B+

•  Related wiring harness

•  Air intake actuator

Moving towards FRESH

1.0 or less

U

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

V

Motor operation (COLD)

Air mix actuator

Moving towards HOT

1.0 or less

•  Related wiring harness

•  Air mix actuator

Moving towards COLD

B+

W

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

X

Motor operation (HOT)

Air mix actuator

Moving towards HOT

B+

•  Related wiring harness

•  Air mix actuator

Moving towards COLD

1.0 or less

Terminal	Signal name	Connected to	Measurement condition	Voltage (V)	Inspection item (s)
A	GND	Body ground	Under any condition	1.0 or less	• Related wiring harness
B	B+	ROOM 15 A fuse	Under any condition	B+	• Related wiring harness • ROOM 15 A fuse
C	—	—	—	—	—
D	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
E	Blower fan speed control	Blower fan controller	(See Blower Fan Speed Control Signal)	• Related wiring harness • Blower fan controller
F	—	—	—	—	—
G	+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)
H	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)
I	—	—	—	—	—
J	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
K	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)
L	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
M	—	—	—	—	—
N	Motor operation (VENT)	Airflow mode actuator	Moving towards VENT	B+	• Related wiring harness • Airflow mode actuator
Moving towards DEFROSTER	1.0 or less
O	—	—	—	—	—
P	Motor operation (DEFROSTER)	Airflow mode actuator	Moving towards DEFROSTER	B+	• Related wiring harness • Airflow mode actuator
Moving towards VENT	1.0 or less
Q	—	—	—	—	—
R	Motor operation (FRESH)	Air intake actuator	Moving towards RECIRCULATE	1.0 or less	• Related wiring harness • Air intake actuator
Moving towards FRESH	B+
S	—	—	—	—	—
T	Motor operation (RECIRCULATE)	Air intake actuator	Moving towards RECIRCULATE	B+	• Related wiring harness • Air intake actuator
Moving towards FRESH	1.0 or less
U	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
V	Motor operation (COLD)	Air mix actuator	Moving towards HOT	1.0 or less	• Related wiring harness • Air mix actuator
Moving towards COLD	B+
W	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
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

• E(+)—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

• E(+)—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

• E(+)—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

• E(+)—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