DTC B1C1C:12, B1C1C:13 [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)]


id0702k2200100

System malfunction location

•  B1C1C:12: Front airflow mode actuator (potentiometer) circuit short to power supply
•  B1C1C:13: Front airflow mode actuator (potentiometer) circuit open
Detection condition
•  Malfunction in wiring harness between front airflow mode actuator and front climate control unit
Fail-safe function
Malfunction determined when ignition switched ON
•  Front airflow mode actuator drive signal is stopped right when the malfunction is determined.
―  However, for manual operation using the MODE switch, vent or defroster mode is available.
Malfunction already exists when ignition switched ON
•  Control based on ambient temperature.
―  However, for manual operation using the MODE switch, vent or defroster mode is available.
Possible cause
R.H.D.:
•  Front airflow mode actuator connector or terminal malfunction
•  Front airflow mode actuator malfunction
•  Front climate control unit connector or terminal malfunction
•  Front climate control unit malfunction
•  Open circuit in wiring harness between the following terminals:
―  Front climate control unit terminal 1C—front airflow mode actuator terminal C
―  Front climate control unit terminal 1B—front airflow mode actuator terminal B
―  Front climate control unit terminal 1Q—front airflow mode actuator terminal A
•  Short to power supply in wiring harness between the following terminals:
―  Front climate control unit terminal 1C—front airflow mode actuator terminal C
―  Front climate control unit terminal 1B—front airflow mode actuator terminal B
―  Front climate control unit terminal 1Q—front airflow mode actuator terminal A
Possible cause
L.H.D.:
•  Front airflow mode actuator connector or terminal malfunction
•  Front airflow mode actuator malfunction
•  Front climate control unit connector or terminal malfunction
•  Front climate control unit malfunction
•  Open circuit in wiring harness between the following terminals:
―  Front climate control unit terminal 1Q—front airflow mode actuator terminal C
―  Front climate control unit terminal 1B—front airflow mode actuator terminal B
―  Front climate control unit terminal 1C—front airflow mode actuator terminal A
•  Short to power supply in wiring harness between the following terminals:
―  Front climate control unit terminal 1Q—front airflow mode actuator terminal C
―  Front climate control unit terminal 1B—front airflow mode actuator terminal B
―  Front climate control unit terminal 1C—front airflow mode actuator terminal A


Diagnostic procedure

STEP

INSPECTION

ACTION

1
INSPECT AIRFLOW MODE ACTUATOR CONNECTOR
•  Switch the ignition off.
•  Disconnect the negative battery terminal.
•  Disconnect the front airflow mode actuator connector.
•  Inspect the connector and terminals (corrosion, damage, pin disconnection).
•  Are the connector and terminals normal?
Yes
Go to the next step.
No
Repair/replace the connector or terminal.
After repair procedure, go to Step 6.
2
INSPECT AIRFLOW MODE ACTUATOR
•  Inspect the front airflow mode actuator.
•  Is it normal?
Yes
Go to the next step.
No
Replace the front airflow mode actuator.
Go to Step 6.
3
VERIFY FRONT CLIMATE CONTROL UNIT CONNECTOR CONDITION
•  Disconnect the front climate control unit connector.
•  Inspect the connector and terminals (corrosion, damage, pin disconnection).
•  Are the connector and terminals normal?
Yes
Go to the next step.
No
Repair/replace the connector or terminal.
After repair procedure, go to Step 6.
4
INSPECT AIRFLOW MODE ACTUATOR (POTENTIOMETER) CIRCUIT FOR OPEN CIRCUIT
•  Front climate control unit and front airflow mode actuator connectors are disconnected.
•  Inspect for continuity between the following terminals (wiring harness-side):
R.H.D.:
―  Front climate control unit terminal 1C—front airflow mode actuator terminal C
―  Front climate control unit terminal 1B—front airflow mode actuator terminal B
―  Front climate control unit terminal 1Q—front airflow mode actuator terminal A
L.H.D.:
―  Front climate control unit terminal 1Q—front airflow mode actuator terminal C
―  Front climate control unit terminal 1B—front airflow mode actuator terminal B
―  Front climate control unit terminal 1C—front airflow mode actuator terminal A
•  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 airflow mode 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 6.
5
INSPECT AIRFLOW MODE ACTUATOR (POTENTIOMETER) CIRCUIT FOR SHORT TO POWER SUPPLY
•  Front climate control unit and front airflow mode actuator 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):
―  Front climate control unit terminal 1C
―  Front climate control unit terminal 1B
―  Front climate control unit terminal 1Q
•  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 airflow mode 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 the next step.
6
VERIFY THAT SAME DTC IS NOT OUTPUT AGAIN
•  Switch the ignition off.
•  Disconnect the negative battery terminal.
•  Reconnect the disconnected connectors.
•  Connect the negative battery terminal.
•  Clear the DTC from the front climate control unit memory using the M-MDS.
•  Perform the DTC inspection for the front climate control unit using the M-MDS.
•  Is the same DTC displayed?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the front climate control unit.
Go to the next step.
No
Go to the next step.
7
VERIFY THAT NO OTHER DTCs ARE PRESENT
•  Verify other DTCs displayed.
•  Are any other DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
No
DTC troubleshooting completed.