CLIMATE CONTROL UNIT INSPECTION [FULL-AUTO AIR CONDITIONER]

id0740a1802200

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1. Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.)

2. Remove the following parts:

(1) Console side panel (See CONSOLE SIDE PANEL REMOVAL/INSTALLATION.)

(2) Switch panel (See SWITCH PANEL REMOVAL/INSTALLATION.)

(3) Cup holder (See CUP HOLDER REMOVAL/INSTALLATION.)

(4) Selector lever knob (ATX) (See SELECTOR LEVER COMPONENT REMOVAL/INSTALLATION.)

(5) Shift lever knob (MTX) (See SHIFT LEVER REMOVAL/INSTALLATION [C66M-R, C66MX-R].) (See SHIFT LEVER REMOVAL/INSTALLATION [D66M-R, D66MX-R].)

(6) Shift panel (See SHIFT PANEL REMOVAL/INSTALLATION.)

(7) Front console box (See FRONT CONSOLE BOX REMOVAL/INSTALLATION.)

(8) Side wall (See SIDE WALL REMOVAL/INSTALLATION.)

(9) Rear console (See REAR CONSOLE REMOVAL/INSTALLATION.)

(10) Driver-side front scuff plate (See FRONT SCUFF PLATE REMOVAL/INSTALLATION.)

(11) Driver-side front side trim (See FRONT SIDE TRIM REMOVAL/INSTALLATION.)

(12) Lower decoration panel (See DECORATION PANEL REMOVAL/INSTALLATION.)

(13) Bonnet release lever (See BONNET RELEASE LEVER AND RELEASE CABLE REMOVAL/INSTALLATION.)

(14) Fuel filer lid opener lever (See FUEL-FILLER LID OPENER AND LEVER REMOVAL/INSTALLATION.)

(15) Driver-side lower panel (See LOWER PANEL REMOVAL/INSTALLATION.)

(16) Center lower panel (See CENTER LOWER PANEL REMOVAL/INSTALLATION.)

3. Remove the climate control unit with the connector connected. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)

4. Connect the negative battery terminal.

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

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

7. Insert the positive (+) lead of the tester into each climate control unit terminal and 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 1T), replace the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)

― For terminal 1T, first try replacing the blower fan controller. (See BLOWER FAN CONTROLLER REMOVAL/INSTALLATION.)

If there is still malfunction, replace the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER].)

Terminal Voltage Table (Reference)

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Terminal

Signal name

Connected to

Measurement condition

Voltage (V)

Inspection item (s)

1A

Cabin temperature sensor input

Cabin temperature sensor

Compared with temperature detected by cabin temperature sensor

Refer to graph 1

•  Related wiring harness

•  Cabin temperature sensor

•  Climate control unit: terminal voltage (1Q)

1B

Potentiometer input

Airflow mode actuator

VENT

4.3

•  Related wiring harness

•  Airflow mode actuator

•  Climate control unit: terminal voltage (1C, 1Q)

BI-LEVEL

3.4

HEAT

2.5

HEAT/DEF

1.6

DEFROSTER

0.7

1C

+5V

•  Air intake actuator

•  Driver-side air mix actuator

•  Passenger-side air mix actuator

•  Airflow mode actuator

•  Solar radiation sensor

Under any condition

5.0

•  Related wiring harness

•  Air intake actuator

•  Driver-side air mix actuator

•  Passenger-side air mix actuator

•  Airflow mode actuator

•  Solar radiation sensor

•  Climate control unit: terminal voltage (1Q)

1D

Potentiometer input

Air intake actuator

RECIRCULATE

1.0

•  Related wiring harness

•  Air intake actuator

•  Climate control unit: terminal voltage (1C, 1Q)

FRESH

3.9

1E

Evaporator temperature sensor input

Evaporator temperature sensor

Compared with temperature detected by evaporator temperature sensor

Refer to graph 2

•  Related wiring harness

•  Evaporator temperature sensor

•  Climate control unit: terminal voltage (1Q)

1F

Solar radiation sensor (RH) input

Solar radiation sensor

Sunlight shined directly on solar radiation sensor

4

•  Related wiring harness

•  Climate control unit: terminal voltage (1C)

•  Solar radiation sensor

Blocking light to solar radiation sensor

1.0 or less

1G

—

—

—

—

—

1H

Solar radiation sensor (LH) input

Solar radiation sensor

Sunlight shined directly on solar radiation sensor

4

•  Related wiring harness

•  Climate control unit: terminal voltage (1C)

•  Solar radiation sensor

Blocking light to solar radiation sensor

1.0 or less

1I

GND

Body ground

Under any condition

1.0 or less

•  Related wiring harness

1J

Motor operation (HOT)

•  Driver-side air mix actuator (L.H.D.)

•  Passenger-side air mix actuator (R.H.D.)

Moving towards HOT

B+

•  Related wiring harness

•  Driver-side air mix actuator (L.H.D.)

•  Passenger-side air mix actuator (R.H.D.)

Moving towards COLD

1.0 or less

1K

MS_CAN_H

CAN related module

Because this terminal is for communication, integrity determination by terminal voltage is not possible.

•  Related wiring harness

1L

Motor operation (COLD)

•  Driver-side air mix actuator (L.H.D.)

•  Passenger-side air mix actuator (R.H.D.)

Moving towards HOT

1.0 or less

•  Related wiring harness

•  Driver-side air mix actuator (L.H.D.)

•  Passenger-side air mix actuator (R.H.D.)

Moving towards COLD

B+

1M

MS_CAN_L

CAN related module

Because this terminal is for communication, integrity determination by terminal voltage is not possible.

•  Related wiring harness

1N

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

1O

—

—

—

—

—

1P

—

—

—

—

—

1Q

Sensor GND

•  Air intake actuator

•  Driver-side air mix actuator

•  Passenger-side air mix actuator

•  Airflow mode actuator

•  Evaporator temperature sensor

•  Cabin temperature sensor

Under any condition

1.0 or less

•  Related wiring harness

1R

—

—

—

—

—

1S

—

—

—

—

—

1T

Blower fan speed control

Blower fan controller

(See Blower Fan Speed Control Signal)

•  Related wiring harness

•  Blower fan controller

1U

B+

ROOM 15 A fuse

Under any condition

B+

•  Related wiring harness

•  ROOM 15 A fuse

1V

—

—

—

—

—

1W

IG1

C/U IG1 15 A fuse

Switch the ignition ON (engine off or on)

B+

•  Related wiring harness

•  C/U IG1 15 A fuse

Switch the ignition off

1.0 or less

1X^*

Front seat warmer switch signal

Front seat warmer control unit

Because this terminal is for communication, determination using terminal voltage inspection is not possible

Seat ventilation switch signal

2A

Motor operation (HOT)

•  Passenger-side air mix actuator (L.H.D.)

•  Driver-side air mix actuator (R.H.D.)

Moving towards HOT

B+

•  Related wiring harness

•  Passenger-side air mix actuator (L.H.D.)

•  Driver-side air mix actuator (R.H.D.)

Moving towards COLD

1.0 or less

2B

Motor operation (DEFROSTER)

Airflow mode actuator

Moving towards DEFROSTER

B+

•  Related wiring harness

•  Airflow mode actuator

Moving towards VENT

1.0 or less

2C

Motor operation (COLD)

•  Passenger-side air mix actuator (L.H.D.)

•  Driver-side air mix actuator (R.H.D.)

Moving towards HOT

1.0 or less

•  Related wiring harness

•  Passenger-side air mix actuator (L.H.D.)

•  Driver-side air mix actuator (R.H.D.)

Moving towards COLD

B+

2D

Motor operation (VENT)

Airflow mode actuator

Moving towards VENT

B+

•  Related wiring harness

•  Airflow mode actuator

Moving towards DEFROSTER

1.0 or less

2E

—

—

—

—

—

2F

Motor operation (RECIRCULATE)

Air intake actuator

Moving towards RECIRCULATE

B+

•  Related wiring harness

•  Air intake actuator

Moving towards FRESH

1.0 or less

2G

—

—

—

—

—

2H

Motor operation (FRESH)

Air intake actuator

Moving towards RECIRCULATE

1.0 or less

•  Related wiring harness

•  Air intake actuator

Moving towards FRESH

B+

2I

Potentiometer input

•  Passenger-side air mix actuator (L.H.D.)

•  Driver-side air mix actuator (R.H.D.)

Set temperature at MAX HOT

4.3

•  Related wiring harness

•  Passenger-side air mix actuator (L.H.D.)

•  Driver-side air mix actuator (R.H.D.)

•  Climate control unit: terminal voltage (1C, 1Q)

Set temperature at MAX COLD

0.7

2J

—

—

—

—

—

2K

Potentiometer input

•  Driver-side air mix actuator (L.H.D.)

•  Passenger-side air mix actuator (R.H.D.)

Set temperature at MAX HOT

4.3

•  Related wiring harness

•  Driver-side air mix actuator (L.H.D.)

•  Passenger-side air mix actuator (R.H.D.)

•  Climate control unit: terminal voltage (1C, 1Q)

Set temperature at MAX COLD

0.7

2L

—

—

—

—

—

Terminal	Signal name	Connected to	Measurement condition	Voltage (V)	Inspection item (s)
1A	Cabin temperature sensor input	Cabin temperature sensor	Compared with temperature detected by cabin temperature sensor	Refer to graph 1	• Related wiring harness • Cabin temperature sensor • Climate control unit: terminal voltage (1Q)
1B	Potentiometer input	Airflow mode actuator	VENT	4.3	• Related wiring harness • Airflow mode actuator • Climate control unit: terminal voltage (1C, 1Q)
BI-LEVEL	3.4
HEAT	2.5
HEAT/DEF	1.6
DEFROSTER	0.7
1C	+5V	• Air intake actuator • Driver-side air mix actuator • Passenger-side air mix actuator • Airflow mode actuator • Solar radiation sensor	Under any condition	5.0	• Related wiring harness • Air intake actuator • Driver-side air mix actuator • Passenger-side air mix actuator • Airflow mode actuator • Solar radiation sensor • Climate control unit: terminal voltage (1Q)
1D	Potentiometer input	Air intake actuator	RECIRCULATE	1.0	• Related wiring harness • Air intake actuator • Climate control unit: terminal voltage (1C, 1Q)
FRESH	3.9
1E	Evaporator temperature sensor input	Evaporator temperature sensor	Compared with temperature detected by evaporator temperature sensor	Refer to graph 2	• Related wiring harness • Evaporator temperature sensor • Climate control unit: terminal voltage (1Q)
1F	Solar radiation sensor (RH) input	Solar radiation sensor	Sunlight shined directly on solar radiation sensor	4	• Related wiring harness • Climate control unit: terminal voltage (1C) • Solar radiation sensor
Blocking light to solar radiation sensor	1.0 or less
1G	—	—	—	—	—
1H	Solar radiation sensor (LH) input	Solar radiation sensor	Sunlight shined directly on solar radiation sensor	4	• Related wiring harness • Climate control unit: terminal voltage (1C) • Solar radiation sensor
Blocking light to solar radiation sensor	1.0 or less
1I	GND	Body ground	Under any condition	1.0 or less	• Related wiring harness
1J	Motor operation (HOT)	• Driver-side air mix actuator (L.H.D.) • Passenger-side air mix actuator (R.H.D.)	Moving towards HOT	B+	• Related wiring harness • Driver-side air mix actuator (L.H.D.) • Passenger-side air mix actuator (R.H.D.)
Moving towards COLD	1.0 or less
1K	MS_CAN_H	CAN related module	Because this terminal is for communication, integrity determination by terminal voltage is not possible.	• Related wiring harness
1L	Motor operation (COLD)	• Driver-side air mix actuator (L.H.D.) • Passenger-side air mix actuator (R.H.D.)	Moving towards HOT	1.0 or less	• Related wiring harness • Driver-side air mix actuator (L.H.D.) • Passenger-side air mix actuator (R.H.D.)
Moving towards COLD	B+
1M	MS_CAN_L	CAN related module	Because this terminal is for communication, integrity determination by terminal voltage is not possible.	• Related wiring harness
1N	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
1O	—	—	—	—	—
1P	—	—	—	—	—
1Q	Sensor GND	• Air intake actuator • Driver-side air mix actuator • Passenger-side air mix actuator • Airflow mode actuator • Evaporator temperature sensor • Cabin temperature sensor	Under any condition	1.0 or less	• Related wiring harness
1R	—	—	—	—	—
1S	—	—	—	—	—
1T	Blower fan speed control	Blower fan controller	(See Blower Fan Speed Control Signal)	• Related wiring harness • Blower fan controller
1U	B+	ROOM 15 A fuse	Under any condition	B+	• Related wiring harness • ROOM 15 A fuse
1V	—	—	—	—	—
1W	IG1	C/U IG1 15 A fuse	Switch the ignition ON (engine off or on)	B+	• Related wiring harness • C/U IG1 15 A fuse
Switch the ignition off	1.0 or less
1X^*	Front seat warmer switch signal	Front seat warmer control unit	Because this terminal is for communication, determination using terminal voltage inspection is not possible
Seat ventilation switch signal
2A	Motor operation (HOT)	• Passenger-side air mix actuator (L.H.D.) • Driver-side air mix actuator (R.H.D.)	Moving towards HOT	B+	• Related wiring harness • Passenger-side air mix actuator (L.H.D.) • Driver-side air mix actuator (R.H.D.)
Moving towards COLD	1.0 or less
2B	Motor operation (DEFROSTER)	Airflow mode actuator	Moving towards DEFROSTER	B+	• Related wiring harness • Airflow mode actuator
Moving towards VENT	1.0 or less
2C	Motor operation (COLD)	• Passenger-side air mix actuator (L.H.D.) • Driver-side air mix actuator (R.H.D.)	Moving towards HOT	1.0 or less	• Related wiring harness • Passenger-side air mix actuator (L.H.D.) • Driver-side air mix actuator (R.H.D.)
Moving towards COLD	B+
2D	Motor operation (VENT)	Airflow mode actuator	Moving towards VENT	B+	• Related wiring harness • Airflow mode actuator
Moving towards DEFROSTER	1.0 or less
2E	—	—	—	—	—
2F	Motor operation (RECIRCULATE)	Air intake actuator	Moving towards RECIRCULATE	B+	• Related wiring harness • Air intake actuator
Moving towards FRESH	1.0 or less
2G	—	—	—	—	—
2H	Motor operation (FRESH)	Air intake actuator	Moving towards RECIRCULATE	1.0 or less	• Related wiring harness • Air intake actuator
Moving towards FRESH	B+
2I	Potentiometer input	• Passenger-side air mix actuator (L.H.D.) • Driver-side air mix actuator (R.H.D.)	Set temperature at MAX HOT	4.3	• Related wiring harness • Passenger-side air mix actuator (L.H.D.) • Driver-side air mix actuator (R.H.D.) • Climate control unit: terminal voltage (1C, 1Q)
Set temperature at MAX COLD	0.7
2J	—	—	—	—	—
2K	Potentiometer input	• Driver-side air mix actuator (L.H.D.) • Passenger-side air mix actuator (R.H.D.)	Set temperature at MAX HOT	4.3	• Related wiring harness • Driver-side air mix actuator (L.H.D.) • Passenger-side air mix actuator (R.H.D.) • Climate control unit: terminal voltage (1C, 1Q)
Set temperature at MAX COLD	0.7
2L	—	—	—	—	—

* :Climate control unit type B with front seat warmer system or seat ventilation system

Blower Fan Speed Control Signal

Fan stopped

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Climate control unit terminal

• 1T(+)—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

• 1T(+)—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

• 1T(+)—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

• 1T(+)—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