FRONT CLIMATE CONTROL UNIT INSPECTION

id074000805100

Note
•  There are two types of front climate control unit, type A and type B.
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1.  Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.)

2.  Remove the following parts:

(1)  Selector lever knob (See AUTOMATIC TRANSAXLE SHIFT MECHANISM REMOVAL/INSTALLATION.)
(2)  Shift panel (See SHIFT PANEL REMOVAL/INSTALLATION.)
(3)  Console side panel (See CONSOLE SIDE PANEL REMOVAL/INSTALLATION.)
(4)  Front console (See FRONT CONSOLE REMOVAL/INSTALLATION.)
(5)  Glove compartment (See GLOVE COMPARTMENT REMOVAL/INSTALLATION.)
(6)  Dashboard under cover (See DASHBOARD UNDER COVER REMOVAL/INSTALLATION.)
(7)  Passenger-side decoration panel (See DECORATION PANEL REMOVAL/INSTALLATION.)
(8)  Front scuff plate (See FRONT SCUFF PLATE REMOVAL/INSTALLATION.)
(9)  Front side trim (See FRONT SIDE TRIM REMOVAL/INSTALLATION.)
(10)  Bonnet release lever (See BONNET RELEASE LEVER AND RELEASE CABLE REMOVAL/INSTALLATION.)
(11)  Fuel-filler lid opener lever (See FUEL-FILLER LID OPENER AND LEVER REMOVAL/INSTALLATION.)
(12)  Driver-side lower panel (See DRIVER-SIDE LOWER PANEL REMOVAL/INSTALLATION.)
(13)  Passenger-side lower panel (See PASSENGER-SIDE LOWER PANEL REMOVAL/INSTALLATION.)
(14)  Side wall (See SIDE WALL REMOVAL/INSTALLATION.)
(15)  Rear console (See REAR CONSOLE REMOVAL/INSTALLATION.)
(16)  Indicator unit (See INDICATOR UNIT REMOVAL/INSTALLATION.)

3.  Remove the front climate control unit with the connector connected. (See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)

4.  Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.)

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 front 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, replace the front climate control unit. (See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)

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Front Climate Control Unit Type A


Terminal voltage table (reference)

Terminal

Signal name

Connected to

Measurement condition

Voltage (V)

Inspection item (s)
1A
MS_CAN_H
CAN related module
Because this terminal is for communication, integrity determination by terminal voltage is not possible.
1B
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
1C
MS_CAN_L
CAN related module
Because this terminal is for communication, integrity determination by terminal voltage is not possible.
1D
—
—
—
—
—
1E
LIN
Rear climate control unit
Because this terminal is for communication, integrity determination by terminal voltage is not possible.
1F
—
—
—
—
—
1G
GND
Body ground
Under any condition
1.0 or less
•  Related wiring harness
1H
Blower fan speed control
Front blower motor
(See Blower fan speed control signal (Front climate control unit type A).)
•  Related wiring harness
•  Front blower motor
1I
Sensor GND
•  Air intake actuator
•  Driver-side front air mix actuator
•  Passenger-side front air mix actuator
•  Front airflow mode actuator
•  Evaporator temperature sensor
•  Cabin temperature sensor
Under any condition
1.0 or less
•  Related wiring harness
•  Front climate control unit: terminal voltage (1R)
1J
Solar radiation sensor (RH) input
Solar radiation sensor
Sunlight shined directly on solar radiation sensor
4
•  Related wiring harness
•  Front climate control unit: terminal voltage (1R)
•  Solar radiation sensor
Blocking light to solar radiation sensor
1.0 or less
1K
—
—
—
—
—
1L
Solar radiation sensor (LH) input
Solar radiation sensor
Sunlight shined directly on solar radiation sensor
4
•  Related wiring harness
•  Front climate control unit: terminal voltage (1R)
•  Solar radiation sensor
Blocking light to solar radiation sensor
1.0 or less
1M
Potentiometer input
•  Passenger-side front air mix actuator (L.H.D.)
•  Driver-side front air mix actuator (R.H.D.)
Set temperature at MAX HOT
4.2
•  Related wiring harness
•  Passenger-side front air mix actuator (L.H.D.)
•  Driver-side front air mix actuator (R.H.D.)
•  Front climate control unit: terminal voltage (1R)
Set temperature at MAX COLD
0.6
1N
Potentiometer input
Air intake actuator
Moving towards RECIRCULATE
3.8
•  Related wiring harness
•  Air intake actuator
•  Front climate control unit: terminal voltage (1R)
Moving towards FRESH
1.4
1O
—
—
—
—
—
1P
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
•  Front climate control unit: terminal voltage (1I)
1Q
—
—
—
—
—
1R
+5V
•  Air intake actuator
•  Driver-side front air mix actuator
•  Passenger-side front air mix actuator
•  Front airflow mode actuator
•  Solar radiation sensor
Under any condition
5
•  Related wiring harness
•  Air intake actuator
•  Driver-side front air mix actuator
•  Passenger-side front air mix actuator
•  Front airflow mode actuator
•  Solar radiation sensor
•  Front climate control unit: terminal voltage (1I)
1S
—
—
—
—
—
1T
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
•  Front climate control unit: terminal voltage (1I)
1U
B+
•  ROOM 25 A fuse
•  INTERIOR 10A fuse
Under any condition
B+
•  Related wiring harness
•  ROOM 25 A fuse
•  INTERIOR 10A fuse
1V
Potentiometer input
Front airflow mode actuator
VENT
0.8
•  Related wiring harness
•  Front airflow mode actuator
•  Front climate control unit: terminal voltage (1R)
BI-LEVEL
1.4
HEAT
2.3
HEAT/DEF
2.9
DEFROSTER
3.8
1W
IG1
With i-stop
•  IGNITION relay (IG1_STAB)
•  METER2 15A fuse
Without i-stop
•  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
Potentiometer input
•  Driver-side front air mix actuator (L.H.D.)
•  Passenger-side front air mix actuator (R.H.D.)
Set temperature at MAX HOT
4.3
•  Related wiring harness
•  Driver-side front air mix actuator (L.H.D.)
•  Passenger-side front air mix actuator (R.H.D.)
•  Front climate control unit: terminal voltage (1R)
Set temperature at MAX COLD
0.6
2A
Motor operation (HOT)
•  Passenger-side front air mix actuator (L.H.D.)
•  Driver-side front air mix actuator (R.H.D.)
Moving towards HOT
B+
•  Related wiring harness
•  Passenger-side front air mix actuator (L.H.D.)
•  Driver-side front air mix actuator (R.H.D.)
Moving towards COLD
1.0 or less
2B
Motor operation (FRESH)
Air intake actuator
Moving towards RECIRCULATE
1.0 or less
•  Related wiring harness
•  Air intake actuator
Moving towards FRESH
B+
2C
Motor operation (COLD)
•  Passenger-side front air mix actuator (L.H.D.)
•  Driver-side front air mix actuator (R.H.D.)
Moving towards HOT
1.0 or less
•  Related wiring harness
•  Passenger-side front air mix actuator (L.H.D.)
•  Driver-side front air mix actuator (R.H.D.)
Moving towards COLD
B+
2D
Motor operation (RECIRCULATE)
Air intake actuator
Moving towards RECIRCULATE
B+
•  Related wiring harness
•  Air intake actuator
Moving towards FRESH
1.0 or less
2E
—
—
—
—
—
2F
Motor operation (HOT)
•  Driver-side front air mix actuator (L.H.D.)
•  Passenger-side front air mix actuator (R.H.D.)
Moving towards HOT
B+
•  Related wiring harness
•  Driver-side front air mix actuator (L.H.D.)
•  Passenger-side front air mix actuator (R.H.D.)
Moving towards COLD
1.0 or less
2G
—
—
—
—
—
2H
Motor operation (COLD)
•  Driver-side front air mix actuator (L.H.D.)
•  Passenger-side front air mix actuator (R.H.D.)
Moving towards HOT
1.0 or less
•  Related wiring harness
•  Driver-side front air mix actuator (L.H.D.)
•  Passenger-side front air mix actuator (R.H.D.)
Moving towards COLD
B+
2I
—
—
—
—
—
2J
Motor operation (DEFROSTER)
Front airflow mode actuator
Moving towards DEFROSTER
B+
•  Related wiring harness
•  Front airflow mode actuator
Moving towards VENT
1.0 or less
2K
—
—
—
—
—
2L
Motor operation (VENT)
Front airflow mode actuator
Moving towards VENT
B+
•  Related wiring harness
•  Front airflow mode actuator
Moving towards DEFROSTER
1.0 or less


Blower fan speed control signal (Front climate control unit type A)

Fan stopped
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Front climate control unit terminal
?  1H(+)—body ground(-)
Oscilloscope setting
?  2 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
?  Switch the ignition ON (engine off or on)
Front climate control unit condition
?  OFF
Manual 1st
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Front climate control unit terminal
?  1H(+)—body ground(-)
Oscilloscope setting
?  2 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
?  Switch the ignition ON (engine off or on)
Front climate control unit condition
?  Airflow mode: VENT
?  Air intake mode: RECIRCULATE
Manual 3rd
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Front climate control unit terminal
?  1H(+)—body ground(-)
Oscilloscope setting
?  2 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
?  Switch the ignition ON (engine off or on)
Front climate control unit condition
?  Airflow mode: VENT
?  Air intake mode: RECIRCULATE
Manual 5th
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Front climate control unit terminal
?  1H(+)—body ground(-)
Oscilloscope setting
?  2 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
?  Switch the ignition ON (engine off or on)
Front climate control unit condition
?  Airflow mode: VENT
?  Air intake mode: RECIRCULATE
Manual 7th
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Front climate control unit terminal
?  1H(+)—body ground(-)
Oscilloscope setting
?  2 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
?  Switch the ignition ON (engine off or on)
Front climate control unit condition
?  Airflow mode: VENT
?  Air intake mode: RECIRCULATE


Front Climate Control Unit Type B


Terminal voltage table (reference)

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 3
•  Related wiring harness
•  Cabin temperature sensor
•  Front climate control unit: terminal voltage (1Q)
1B
Potentiometer input
Front airflow mode actuator
VENT
0.8
•  Related wiring harness
•  Front airflow mode actuator
•  Front climate control unit: terminal voltage (1C)
BI-LEVEL
1.4
HEAT
2.3
HEAT/DEF
2.9
DEFROSTER
3.8
1C
+5V
•  Air intake actuator
•  Driver-side front air mix actuator
•  Passenger-side front air mix actuator
•  Front airflow mode actuator
•  Solar radiation sensor
Under any condition
5
•  Related wiring harness
•  Air intake actuator
•  Driver-side front air mix actuator
•  Passenger-side front air mix actuator
•  Front airflow mode actuator
•  Solar radiation sensor
•  Front climate control unit: terminal voltage (1Q)
1D
Potentiometer input
Air intake actuator
Moving towards RECIRCULATE
3.8
•  Related wiring harness
•  Air intake actuator
•  Front climate control unit: terminal voltage (1C)
Moving towards FRESH
1.4
1E
Evaporator temperature sensor input
Evaporator temperature sensor
Compared with temperature detected by evaporator temperature sensor
Refer to graph 4
•  Related wiring harness
•  Evaporator temperature sensor
•  Front 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
•  Front 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
•  Front 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 front air mix actuator (L.H.D.)
•  Passenger-side front air mix actuator (R.H.D.)
Moving towards HOT
B+
•  Related wiring harness
•  Driver-side front air mix actuator (L.H.D.)
•  Passenger-side front 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.
1L
Motor operation (COLD)
•  Driver-side front air mix actuator (L.H.D.)
•  Passenger-side front air mix actuator (R.H.D.)
Moving towards HOT
1.0 or less
•  Related wiring harness
•  Driver-side front air mix actuator (L.H.D.)
•  Passenger-side front 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.
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
LIN
Rear climate control unit
Because this terminal is for communication, integrity determination by terminal voltage is not possible.
1P
—
—
—
—
—
1Q
Sensor GND
•  Air intake actuator
•  Driver-side front air mix actuator
•  Passenger-side front air mix actuator
•  Front airflow mode actuator
•  Evaporator temperature sensor
•  Cabin temperature sensor
Under any condition
1.0 or less
•  Related wiring harness
•  Front climate control unit: terminal voltage (1C)
1R
—
—
—
—
—
1S
—
—
—
—
—
1T
Blower fan speed control
Front blower motor
(See Blower fan speed control signal (Front climate control unit type B).)
•  Related wiring harness
•  Front blower motor
1U
B+
•  ROOM 25 A fuse
•  INTERIOR 10A fuse
Under any condition
B+
•  Related wiring harness
•  ROOM 25 A fuse
•  INTERIOR 10A fuse
1V
—
—
—
—
—
1W
IG1
With i-stop
•  IGNITION relay (IG1_STAB)
•  METER2 15A fuse
Without i-stop
•  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
Because this terminal is for communication, determination using terminal voltage inspection is not possible
2A
Motor operation (HOT)
•  Passenger-side front air mix actuator (L.H.D.)
•  Driver-side front air mix actuator (R.H.D.)
Moving towards HOT
B+
•  Related wiring harness
•  Passenger-side front air mix actuator (L.H.D.)
•  Driver-side front air mix actuator (R.H.D.)
Moving towards COLD
1.0 or less
2B
Motor operation (DEFROSTER)
Front airflow mode actuator
Moving towards DEFROSTER
B+
•  Related wiring harness
•  Front airflow mode actuator
Moving towards VENT
1.0 or less
2C
Motor operation (COLD)
•  Passenger-side front air mix actuator (L.H.D.)
•  Driver-side front air mix actuator (R.H.D.)
Moving towards HOT
1.0 or less
•  Related wiring harness
•  Passenger-side front air mix actuator (L.H.D.)
•  Driver-side front air mix actuator (R.H.D.)
Moving towards COLD
B+
2D
Motor operation (VENT)
Front airflow mode actuator
Moving towards VENT
B+
•  Related wiring harness
•  Front 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 front air mix actuator (L.H.D.)
•  Driver-side front air mix actuator (R.H.D.)
Set temperature at MAX HOT
4.2
•  Related wiring harness
•  Passenger-side front air mix actuator (L.H.D.)
•  Driver-side front air mix actuator (R.H.D.)
•  Front climate control unit: terminal voltage (1C)
Set temperature at MAX COLD
0.6
2J
—
—
—
—
—
2K
Potentiometer input
•  Driver-side front air mix actuator (L.H.D.)
•  Passenger-side front air mix actuator (R.H.D.)
Set temperature at MAX HOT
4.3
•  Related wiring harness
•  Driver-side front air mix actuator (L.H.D.)
•  Passenger-side front air mix actuator (R.H.D.)
•  Front climate control unit: terminal voltage (1C)
Set temperature at MAX COLD
0.6
2L
—
—
—
—
—


Blower fan speed control signal (Front climate control unit type B)

Fan stopped
ac9uuw00009654
Front climate control unit terminal
?  1T(+)—body ground(-)
Oscilloscope setting
?  2 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
?  Switch the ignition ON (engine off or on)
Front climate control unit condition
?  OFF
Manual 1st
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Front climate control unit terminal
?  1T(+)—body ground(-)
Oscilloscope setting
?  2 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
?  Switch the ignition ON (engine off or on)
Front climate control unit condition
?  Airflow mode: VENT
?  Air intake mode: RECIRCULATE
Manual 3rd
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Front climate control unit terminal
?  1T(+)—body ground(-)
Oscilloscope setting
?  2 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
?  Switch the ignition ON (engine off or on)
Front climate control unit condition
?  Airflow mode: VENT
?  Air intake mode: RECIRCULATE
Manual 5th
ac9uuw00009657
Front climate control unit terminal
?  1T(+)—body ground(-)
Oscilloscope setting
?  2 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
?  Switch the ignition ON (engine off or on)
Front climate control unit condition
?  Airflow mode: VENT
?  Air intake mode: RECIRCULATE
Manual 7th
ac9uuw00009658
Front climate control unit terminal
?  1T(+)—body ground(-)
Oscilloscope setting
?  2 V/DIV (Y), 1 ms/DIV (X), DC range
Vehicle condition
?  Switch the ignition ON (engine off or on)
Front climate control unit condition
?  Airflow mode: VENT
?  Air intake mode: RECIRCULATE