DUAL A/C CONTROL DOES NOT OPERATE [CLIMATE CONTROL SYSTEM]

id0703k2701100

Note
•  There are two types of front climate control unit, type A and type B.
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Front Climate Control Unit Type A

DESCRIPTION
•  Driver or passenger side temperature control dial does not operate individually
•  Temperature control operates normally except for dual A/C control function
POSSIBLE CAUSE
•  Front air mix door malfunction (driver or passenger-side)
•  Front air mix actuator malfunction (driver or passenger-side)
•  Open or short circuit in wiring or poor connection between front climate control unit and front air mix actuator (driver or passenger-side)
•  Front climate control unit malfunction
•  When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while doing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, inspect to make sure connectors, terminals and wiring harness are connected correctly and undamaged.

Diagnostic procedure

Step

Inspection

Action
1
VERIFY SYMPTOM
•  Turn on the A/C.
•  Perform the dual A/C control function for driver and passenger side individually.
•  Is it either the temperature control on driver side or passenger side?
Yes
Go to the next step.
No
Go to Step 12.
2
INSPECT TO SEE WHETHER MALFUNCTION IS IN FRONT AIR MIX DOOR OR ELSEWHERE
•  Turn on the A/C.
•  Change temperature control on the suspected side while in dual mode.
•  Does the front air mix door on the suspect side move smoothly?
Yes
Go to Step 8.
No
Go to the next step.
3
INSPECT FRONT AIR MIX ACTUATOR
•  Inspect the front air mix actuator on the suspect side.
•  Is the front air mix actuator normal?
Yes
Go to the next step.
No
Replace the front air mix actuator on the suspected side, then go to Step 15.
(See FRONT AIR MIX ACTUATOR REMOVAL/INSTALLATION.)
4*
INSPECT FRONT AIR MIX ACTUATOR CIRCUIT FOR SHORT TO GROUND
•  Disconnect the front climate control unit connector.
•  Inspect for continuity between the following terminals (wiring harness-side) and body ground:
L.H.D. (Driver-side)
?  Front climate control unit terminal 2F
?  Front climate control unit terminal 2H
L.H.D. (Passenger-side)
?  Front climate control unit terminal 2A
?  Front climate control unit terminal 2C
R.H.D. (Driver-side)
?  Front climate control unit terminal 2A
?  Front climate control unit terminal 2C
R.H.D. (Passenger-side)
?  Front climate control unit terminal 2F
?  Front climate control unit terminal 2H
•  Is there continuity?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
Go to Step 15.
No
Go to the next step.
5*
INSPECT FRONT AIR MIX ACTUATOR CIRCUIT FOR OPEN CIRCUIT
•  Front air mix actuator and front climate control unit connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
L.H.D. (Driver-side)
?  Front climate control unit terminal 2F—front air mix actuator terminal D
?  Front climate control unit terminal 2H—front air mix actuator terminal E
L.H.D. (Passenger-side)
?  Front climate control unit terminal 2A—front air mix actuator terminal E
?  Front climate control unit terminal 2C—front air mix actuator terminal D
R.H.D. (Driver-side)
?  Front climate control unit terminal 2A—front air mix actuator terminal E
?  Front climate control unit terminal 2C—front air mix actuator terminal D
R.H.D. (Passenger-side)
?  Front climate control unit terminal 2F—front air mix actuator terminal D
?  Front climate control unit terminal 2H—front air mix actuator terminal E
•  Is there continuity?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 15.
6*
INSPECT FRONT AIR MIX ACTUATOR CIRCUIT FOR SHORT TO POWER SUPPLY
•  Front air mix actuator and front climate control unit connectors are disconnected.
•  Connect the negative battery terminal.
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at the following terminals (wiring harness-side):
L.H.D. (Driver-side)
?  Front climate control unit terminal 2F
?  Front climate control unit terminal 2H
L.H.D. (Passenger-side)
?  Front climate control unit terminal 2A
?  Front climate control unit terminal 2C
R.H.D. (Driver-side)
?  Front climate control unit terminal 2A
?  Front climate control unit terminal 2C
R.H.D. (Passenger-side)
?  Front climate control unit terminal 2F
?  Front climate control unit terminal 2H
•  Is the voltage 0 V?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to power supply.
Go to Step 15.
7
INSPECT FRONT AIR MIX DOOR
•  Inspect the suspect side front air mix door.
•  Is the front air mix door normal?
Yes
Replace the front climate control unit, then go to Step 15.
(See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)
No
Remove the obstruction or replace front A/C unit case on the suspected side, then go to Step 15.
(See FRONT A/C UNIT DISASSEMBLY/ASSEMBLY.)
8*
INSPECT FRONT AIR MIX ACTUATOR POSITION SENSOR
•  Inspect the front air mix actuator position sensor on the suspected side.
•  Is the front air mix actuator position sensor normal?
Yes
Go to the next step.
No
Replace the front air mix actuator on the suspected side, then go to Step 15.
(See FRONT AIR MIX ACTUATOR REMOVAL/INSTALLATION.)
9*
INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO GROUND
•  Disconnect the front climate control unit connector.
•  Inspect for continuity between the following terminals (wiring harness-side) and body ground:
L.H.D. (Driver-side)
?  Front climate control unit terminal 1X
L.H.D. (Passenger-side)
?  Front climate control unit terminal 1M
R.H.D. (Driver-side)
?  Front climate control unit terminal 1M
R.H.D. (Passenger-side)
?  Front climate control unit terminal 1X
•  Is there continuity?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
Go to Step 15.
No
Go to the next step.
10*
INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR OPEN CIRCUIT
•  Front air mix actuator and front climate control unit connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
L.H.D. (Driver-side)
?  Front climate control unit terminal 1X—front air mix actuator terminal B
?  Front climate control unit terminal 1R—front air mix actuator terminal A
?  Front climate control unit terminal 1I—front air mix actuator terminal C
L.H.D. (Passenger-side)
?  Front climate control unit terminal 1M—front air mix actuator terminal B
?  Front climate control unit terminal 1R—front air mix actuator terminal C
?  Front climate control unit terminal 1I—front air mix actuator terminal A
R.H.D. (Driver-side)
?  Front climate control unit terminal 1M—front air mix actuator terminal B
?  Front climate control unit terminal 1R—front air mix actuator terminal C
?  Front climate control unit terminal 1I—front air mix actuator terminal A
R.H.D. (Passenger-side)
?  Front climate control unit terminal 1X—front air mix actuator terminal B
?  Front climate control unit terminal 1R—front air mix actuator terminal A
?  Front climate control unit terminal 1I—front air mix actuator terminal C
•  Is there continuity?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 15.
11*
INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO POWER SUPPLY
•  Front air mix actuator and front climate control unit connectors are disconnected.
•  Connect the negative battery terminal.
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at the following terminals (wiring harness-side):
L.H.D. (Driver-side)
?  Front climate control unit terminal 1X
L.H.D. (Passenger-side)
?  Front climate control unit terminal 1M
R.H.D. (Driver-side)
?  Front climate control unit terminal 1M
R.H.D. (Passenger-side)
?  Front climate control unit terminal 1X
•  Is the voltage 0 V?
Yes
Replace the front climate control unit, then go to Step 15.
(See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)
No
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to power supply.
Go to Step 15.
12*
INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO GROUND
•  Switch the ignition off.
•  Disconnect the negative battery terminal.
•  Disconnect the front climate control unit connector.
•  Disconnect the front air mix actuator connector.
•  Inspect for continuity between the following terminals (wiring harness-side) and body ground:
?  Front climate control unit terminal 1R
?  Front climate control unit terminal 1I
•  Is there continuity?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and each front actuator / sensor terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
Go to Step 15.
No
Go to the next step.
13*
INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR OPEN CIRCUIT
•  Front air mix actuator and front climate control unit connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
L.H.D. (Driver-side)
?  Front climate control unit terminal 1R—Front air mix actuator terminal A
?  Front climate control unit terminal 1I—Front air mix actuator terminal C
L.H.D. (Passenger-side)
?  Front climate control unit terminal 1R—Front air mix actuator terminal C
?  Front climate control unit terminal 1I—Front air mix actuator terminal A
R.H.D. (Driver-side)
?  Front climate control unit terminal 1R—Front air mix actuator terminal C
?  Front climate control unit terminal 1I—Front air mix actuator terminal A
R.H.D. (Passenger-side)
?  Front climate control unit terminal 1R—Front air mix actuator terminal A
?  Front climate control unit terminal 1I—Front air mix actuator terminal C
•  Is there continuity?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 15.
14*
INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO POWER SUPPLY
•  Front air mix actuator and front climate control unit connectors are disconnected.
•  Connect the negative battery terminal.
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at the terminals (wiring harness-side):
?  Front climate control unit terminal 1R
?  Front climate control unit terminal 1I
•  Is the voltage 0 V?
Yes
Replace the front climate control unit.
(See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)
Go to the next Step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and each front actuator / sensor terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to power supply.
Go to the next step.
15
VERIFY THAT MALFUNCTION SYMPTOMS DO NOT RECUR AFTER REPAIR
•  Can the temperatures for the driver-side and passenger-side be adjusted independently?
Yes
Troubleshooting completed. Explain repairs to customer.
No
Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.


Front Climate Control Unit Type B

DESCRIPTION
•  Driver or passenger side temperature control dial does not operate individually
•  Temperature control operates normally except for dual A/C control function
POSSIBLE CAUSE
•  Front air mix door malfunction (driver or passenger-side)
•  Front air mix actuator malfunction (driver or passenger-side)
•  Open or short circuit in wiring or poor connection between front climate control unit and front air mix actuator (driver or passenger-side)
•  Front climate control unit malfunction
•  When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while doing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, inspect to make sure connectors, terminals and wiring harness are connected correctly and undamaged.

Diagnostic procedure

Step

Inspection

Action
1
VERIFY SYMPTOM
•  Turn on the A/C.
•  Perform the dual A/C control function for driver and passenger side individually.
•  Is it either the temperature control on driver side or passenger side?
Yes
Go to the next step.
No
Go to Step 12.
2
INSPECT TO SEE WHETHER MALFUNCTION IS IN FRONT AIR MIX DOOR OR ELSEWHERE
•  Turn on the A/C.
•  Change temperature control on the suspected side while in dual mode.
•  Does the front air mix door on the suspect side move smoothly?
Yes
Go to Step 8.
No
Go to the next step.
3
INSPECT FRONT AIR MIX ACTUATOR
•  Inspect the front air mix actuator on the suspect side.
•  Is the front air mix actuator normal?
Yes
Go to the next step.
No
Replace the front air mix actuator on the suspected side, then go to Step 15.
(See FRONT AIR MIX ACTUATOR REMOVAL/INSTALLATION.)
4*
INSPECT FRONT AIR MIX ACTUATOR CIRCUIT FOR SHORT TO GROUND
•  Disconnect the front climate control unit connector.
•  Inspect for continuity between the following terminals (wiring harness-side) and body ground:
L.H.D. (Driver-side)
?  Front climate control unit terminal 1J
?  Front climate control unit terminal 1L
L.H.D. (Passenger-side)
?  Front climate control unit terminal 2A
?  Front climate control unit terminal 2C
R.H.D. (Driver-side)
?  Front climate control unit terminal 2A
?  Front climate control unit terminal 2C
R.H.D. (Passenger-side)
?  Front climate control unit terminal 1J
?  Front climate control unit terminal 1L
•  Is there continuity?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
Go to Step 15.
No
Go to the next step.
5*
INSPECT FRONT AIR MIX ACTUATOR CIRCUIT FOR OPEN CIRCUIT
•  Front air mix actuator and front climate control unit connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
L.H.D. (Driver-side)
?  Front climate control unit terminal 1J—front air mix actuator terminal D
?  Front climate control unit terminal 1L—front air mix actuator terminal E
L.H.D. (Passenger-side)
?  Front climate control unit terminal 2A—front air mix actuator terminal E
?  Front climate control unit terminal 2C—front air mix actuator terminal D
R.H.D. (Driver-side)
?  Front climate control unit terminal 2A—front air mix actuator terminal E
?  Front climate control unit terminal 2C—front air mix actuator terminal D
R.H.D. (Passenger-side)
?  Front climate control unit terminal 1J—front air mix actuator terminal D
?  Front climate control unit terminal 1L—front air mix actuator terminal E
•  Is there continuity?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 15.
6*
INSPECT FRONT AIR MIX ACTUATOR CIRCUIT FOR SHORT TO POWER SUPPLY
•  Front air mix actuator and front climate control unit connectors are disconnected.
•  Connect the negative battery terminal.
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at the following terminals (wiring harness-side):
L.H.D. (Driver-side)
?  Front climate control unit terminal 1J
?  Front climate control unit terminal 1L
L.H.D. (Passenger-side)
?  Front climate control unit terminal 2A
?  Front climate control unit terminal 2C
R.H.D. (Driver-side)
?  Front climate control unit terminal 2A
?  Front climate control unit terminal 2C
R.H.D. (Passenger-side)
?  Front climate control unit terminal 1J
?  Front climate control unit terminal 1L
•  Is the voltage 0 V?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to power supply.
Go to Step 15.
7
INSPECT FRONT AIR MIX DOOR
•  Inspect the suspect side front air mix door.
•  Is the front air mix door normal?
Yes
Replace the front climate control unit, then go to Step 15.
(See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)
No
Remove the obstruction or replace front A/C unit case on the suspected side, then go to Step 15.
(See FRONT A/C UNIT DISASSEMBLY/ASSEMBLY.)
8*
INSPECT FRONT AIR MIX ACTUATOR POSITION SENSOR
•  Inspect the front air mix actuator position sensor on the suspected side.
•  Is the front air mix actuator position sensor normal?
Yes
Go to the next step.
No
Replace the front air mix actuator on the suspected side, then go to Step 15.
(See FRONT AIR MIX ACTUATOR REMOVAL/INSTALLATION.)
9*
INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO GROUND
•  Disconnect the front climate control unit connector.
•  Inspect for continuity between the following terminals (wiring harness-side) and body ground:
L.H.D. (Driver-side)
?  Front climate control unit terminal 2K
L.H.D. (Passenger-side)
?  Front climate control unit terminal 2I
R.H.D. (Driver-side)
?  Front climate control unit terminal 2I
R.H.D. (Passenger-side)
?  Front climate control unit terminal 2K
•  Is there continuity?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
Go to Step 15.
No
Go to the next step.
10*
INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR OPEN CIRCUIT
•  Front air mix actuator and front climate control unit connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
L.H.D. (Driver-side)
?  Front climate control unit terminal 2K—front air mix actuator terminal B
?  Front climate control unit terminal 1C—front air mix actuator terminal A
?  Front climate control unit terminal 1Q—front air mix actuator terminal C
L.H.D. (Passenger-side)
?  Front climate control unit terminal 2I—front air mix actuator terminal B
?  Front climate control unit terminal 1C—front air mix actuator terminal C
?  Front climate control unit terminal 1Q—front air mix actuator terminal A
R.H.D. (Driver-side)
?  Front climate control unit terminal 2I—front air mix actuator terminal B
?  Front climate control unit terminal 1C—front air mix actuator terminal C
?  Front climate control unit terminal 1Q—front air mix actuator terminal A
R.H.D. (Passenger-side)
?  Front climate control unit terminal 2K—front air mix actuator terminal B
?  Front climate control unit terminal 1C—front air mix actuator terminal A
?  Front climate control unit terminal 1Q—front air mix actuator terminal C
•  Is there continuity?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 15.
11*
INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO POWER SUPPLY
•  Front air mix actuator and front climate control unit connectors are disconnected.
•  Connect the negative battery terminal.
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at the following terminals (wiring harness-side):
L.H.D. (Driver-side)
?  Front climate control unit terminal 2K
L.H.D. (Passenger-side)
?  Front climate control unit terminal 2I
R.H.D. (Driver-side)
?  Front climate control unit terminal 2I
R.H.D. (Passenger-side)
?  Front climate control unit terminal 2K
•  Is the voltage 0 V?
Yes
Replace the front climate control unit, then go to Step 15.
(See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)
No
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to power supply.
Go to Step 15.
12*
INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO GROUND
•  Switch the ignition off.
•  Disconnect the negative battery terminal.
•  Disconnect the front climate control unit connector.
•  Disconnect the front air mix actuator connector.
•  Inspect for continuity between the following terminals (wiring harness-side) and body ground:
?  Front climate control unit terminal 1C
?  Front climate control unit terminal 1Q
•  Is there continuity?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and each front actuator / sensor terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to ground.
Go to Step 15.
No
Go to the next step.
13*
INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR OPEN CIRCUIT
•  Front air mix actuator and front climate control unit connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
L.H.D. (Driver-side)
?  Front climate control unit terminal 1C—Front air mix actuator terminal A
?  Front climate control unit terminal 1Q—Front air mix actuator terminal C
L.H.D. (Passenger-side)
?  Front climate control unit terminal 1C—Front air mix actuator terminal C
?  Front climate control unit terminal 1Q—Front air mix actuator terminal A
R.H.D. (Driver-side)
?  Front climate control unit terminal 1C—Front air mix actuator terminal C
?  Front climate control unit terminal 1Q—Front air mix actuator terminal A
R.H.D. (Passenger-side)
?  Front climate control unit terminal 1C—Front air mix actuator terminal A
?  Front climate control unit terminal 1Q—Front air mix actuator terminal C
•  Is there continuity?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and front air mix actuator terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 15.
14*
INSPECT FRONT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO POWER SUPPLY
•  Front air mix actuator and front climate control unit connectors are disconnected.
•  Connect the negative battery terminal.
•  Switch the ignition ON (engine off or on).
•  Measure the voltage at the terminals (wiring harness-side):
?  Front climate control unit terminal 1C
?  Front climate control unit terminal 1Q
•  Is the voltage 0 V?
Yes
Replace the front climate control unit.
(See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.)
Go to the next Step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between front climate control unit terminal and each front actuator / sensor terminal.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has a short to power supply.
Go to the next step.
15
VERIFY THAT MALFUNCTION SYMPTOMS DO NOT RECUR AFTER REPAIR
•  Can the temperatures for the driver-side and passenger-side be adjusted independently?
Yes
Troubleshooting completed. Explain repairs to customer.
No
Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.