DTC B1C1C:12, B1C1C:13 [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)] - MAZDA CX-9 TC 2016

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

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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

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	• Connector or terminal malfunction • Front airflow mode actuator malfunction • Open circuit in wiring harness between front climate control unit and front airflow mode actuator • Short to power supply in wiring harness between front climate control unit and front airflow mode actuator • Front climate control unit malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	INSPECT FRONT AIRFLOW MODE ACTUATOR CONNECTOR • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the front airflow mode actuator connector. (See FRONT AIRFLOW MODE ACTUATOR REMOVAL.) • Inspect the connector and terminals (corrosion, damage, pin disconnection). • Are the connector and terminals normal?	Yes	Go to the next step.
1		No	Repair/replace the connector or terminal. After repair procedure, go to Step 6.
2	INSPECT FRONT AIRFLOW MODE ACTUATOR • Inspect the front airflow mode actuator. (See FRONT AIRFLOW MODE ACTUATOR INSPECTION.) • Is it normal?	Yes	Go to the next step.
2		No	Replace the front airflow mode actuator. (See FRONT AIRFLOW MODE ACTUATOR INSTALLATION.) Go to Step 6.
3	INSPECT FRONT AIRFLOW MODE ACTUATOR (POTENTIOMETER) CIRCUIT FOR OPEN CIRCUIT • Disconnect the front climate control unit connector. (See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.) • Inspect for continuity between the following terminals (wiring harness-side): L.H.D. ? Front climate control unit terminal 1R—front airflow mode actuator terminal A ? Front climate control unit terminal 1V—front airflow mode actuator terminal B ? Front climate control unit terminal 1I—front airflow mode actuator terminal C R.H.D. ? Front climate control unit terminal 1R—front airflow mode actuator terminal C ? Front climate control unit terminal 1V—front airflow mode actuator terminal B ? Front climate control unit terminal 1I—front airflow mode actuator terminal A • Is there continuity?	Yes	Go to the next step.
3		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.
4	INSPECT FRONT AIRFLOW MODE ACTUATOR (POTENTIOMETER) CIRCUIT FOR SHORT TO POWER SUPPLY • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Switch the ignition ON (engine off or on). • Measure the voltage at the following terminals (wiring harness-side): ? Front climate control unit terminal 1R ? Front climate control unit terminal 1V ? Front climate control unit terminal 1I • Is the voltage 0 V?	Yes	Go to the next step.
4		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 Step 6.
5	VERIFY FRONT CLIMATE CONTROL UNIT CONNECTOR CONDITION • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Inspect the connector and terminals (corrosion, damage, pin disconnection). • Are the connector and terminals normal?	Yes	Go to the next step.
5		No	Repair/replace the connector or terminal. After repair procedure, go to the next step.
6	VERIFY THAT SAME DTC IS NOT OUTPUT AGAIN • Reconnect the disconnected connectors. • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Clear the DTC from the climate control unit memory using the M-MDS. (See CLEARING DTC [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)].) • Perform the DTC inspection for the climate control unit using the M-MDS. (See DTC DISPLAY [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)].) • Is the same DTC displayed?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the front climate control unit. (See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.) Go to the next step.
6		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. (See DTC TABLE [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)].)
7		No	DTC troubleshooting completed.

Front Climate Control Unit Type B

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	• Connector or terminal malfunction • Front airflow mode actuator malfunction • Open circuit in wiring harness between front climate control unit and front airflow mode actuator • Short to power supply in wiring harness between front climate control unit and front airflow mode actuator • Front climate control unit malfunction

Diagnostic procedure

STEP	INSPECTION		ACTION
1	INSPECT FRONT AIRFLOW MODE ACTUATOR CONNECTOR • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Disconnect the front airflow mode actuator connector. (See FRONT AIRFLOW MODE ACTUATOR REMOVAL.) • Inspect the connector and terminals (corrosion, damage, pin disconnection). • Are the connector and terminals normal?	Yes	Go to the next step.
1		No	Repair/replace the connector or terminal. After repair procedure, go to Step 6.
2	INSPECT FRONT AIRFLOW MODE ACTUATOR • Inspect the front airflow mode actuator. (See FRONT AIRFLOW MODE ACTUATOR INSPECTION.) • Is it normal?	Yes	Go to the next step.
2		No	Replace the front airflow mode actuator. (See FRONT AIRFLOW MODE ACTUATOR INSTALLATION.) Go to Step 6.
3	INSPECT FRONT AIRFLOW MODE ACTUATOR (POTENTIOMETER) CIRCUIT FOR OPEN CIRCUIT • Disconnect the front climate control unit connector. (See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.) • Inspect for continuity between the following terminals (wiring harness-side): L.H.D. ? Front climate control unit terminal 1C—front airflow mode actuator terminal A ? Front climate control unit terminal 1B—front airflow mode actuator terminal B ? Front climate control unit terminal 1Q—front airflow mode actuator terminal C 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 • Is there continuity?	Yes	Go to the next step.
3		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.
4	INSPECT FRONT AIRFLOW MODE ACTUATOR (POTENTIOMETER) CIRCUIT FOR SHORT TO POWER SUPPLY • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • 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.
4		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 Step 6.
5	VERIFY FRONT CLIMATE CONTROL UNIT CONNECTOR CONDITION • Switch the ignition off. • Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Inspect the connector and terminals (corrosion, damage, pin disconnection). • Are the connector and terminals normal?	Yes	Go to the next step.
5		No	Repair/replace the connector or terminal. After repair procedure, go to the next step.
6	VERIFY THAT SAME DTC IS NOT OUTPUT AGAIN • Reconnect the disconnected connectors. • Connect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION.) • Clear the DTC from the climate control unit memory using the M-MDS. (See CLEARING DTC [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)].) • Perform the DTC inspection for the climate control unit using the M-MDS. (See DTC DISPLAY [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)].) • Is the same DTC displayed?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the front climate control unit. (See FRONT CLIMATE CONTROL UNIT REMOVAL/INSTALLATION.) Go to the next step.
6		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. (See DTC TABLE [CLIMATE CONTROL UNIT (FULL-AUTO AIR CONDITIONER)].)
7		No	DTC troubleshooting completed.