Diagnostic Procedure

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.

INSUFFICIENT AIR (OR NO AIR) BLOWN FROM VENTS (AUTO A/C) DIAGNOSTIC PROCEDURE

Step	Inspection		Action
1	PERFORM DASH-ELECTRICAL SUPPLY UNIT DTC INSPECTION Perform the dash-electrical supply unit DTC inspection using the M-MDS. (See DTC INSPECTION .) Are any DTCs displayed?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [DASH-ELECTRICAL SUPPLY UNIT (US)] .)
1		No	Go to the next step.
2	VERIFY BLOWER MOTOR OPERATION Switch the ignition ON (engine off or on). Turn the blower motor on. Does air flow from the vent after operating the blower motor?	Yes	Go to the next step.
2		No	Go to the following malfunction symptom item. (See AMOUNT OF AIR BLOWN FROM VENTS DOES NOT CHANGE (AUTO A/C) (US) .)
3	VERIFY AIRFLOW CONDITION Does air flow from the vent when the airflow mode is in the VENT mode?	Yes	Go to Step 7.
3		No	Go to the next step.
4	VERIFY VENT CONDITION Is the air vent (right and left/center) closed?	Yes	Open the air vent, then perform the repair completion verification.
4		No	Go to the next step.
5	INSPECT AIR VENT FOR BLOCKAGE Is the air vent blocked?	Yes	Remove the obstruction, then perform the repair completion verification.
5	INSPECT AIR VENT FOR BLOCKAGE Is the air vent blocked?	No	Go to the next step.
6	VERIFY DUCT INSTALLATION CONDITION Is the duct (installed to dashboard) installed to the position correctly and securely? (See DASHBOARD REMOVAL [(US)] .) (See DASHBOARD INSTALLATION [(US)] .)	Yes	Inspect ducts for restriction, deformity, and air leakage, then perform the repair completion verification.
6		No	Install the incorrectly installed ducts properly, then perform the repair completion verification. (See DASHBOARD DISASSEMBLY/ASSEMBLY [(US)] .)
7	VERIFY AIRFLOW CONDITION Does air flow from the vent when the airflow mode is in the HEAT mode?	Yes	Go to Step 10.
7		No	Go to the next step.
8	INSPECT AIR VENT FOR BLOCKAGE Is the air vent blocked?	Yes	Remove the obstruction, then perform the repair completion verification.
8	INSPECT AIR VENT FOR BLOCKAGE Is the air vent blocked?	No	Go to the next step.
9	VERIFY DUCT INSTALLATION CONDITION Is the duct installed to the position correctly and securely? (See FRONT HEAT DUCT REMOVAL/INSTALLATION [(US)] .) (See REAR HEAT DUCT REMOVAL/INSTALLATION [(US)] .)	Yes	Inspect ducts for restriction, deformity, and air leakage, then perform the repair completion verification.
9		No	Install the incorrectly installed ducts properly, then perform the repair completion verification. (See FRONT HEAT DUCT REMOVAL/INSTALLATION [(US)] .) (See REAR HEAT DUCT REMOVAL/INSTALLATION [(US)] .)
10	VERIFY AIRFLOW CONDITION Does air flow from the vent when the airflow mode is in the DEFROSTER mode?	Yes	Perform the repair completion verification.
10		No	Go to the next step.
11	INSPECT AIR VENT FOR BLOCKAGE Is the air vent blocked?	Yes	Remove the obstruction, then perform the repair completion verification.
11	INSPECT AIR VENT FOR BLOCKAGE Is the air vent blocked?	No	Go to the next step.
12	INSPECT AIRFLOW MODE ACTUATOR Inspect the airflow mode actuator. (See AIRFLOW MODE ACTUATOR INSPECTION (AUTO A/C) .) Is it normal?	Yes	Go to the next step.
12		No	Replace the airflow mode actuator, then perform the repair completion verification. (See AIRFLOW MODE ACTUATOR REMOVAL (AUTO A/C) (US) .) (See AIRFLOW MODE ACTUATOR INSTALLATION (AUTO A/C) (US) .)
13	INSPECT AIRFLOW MODE LINK SET OPERATION Operate the airflow mode link set manually. Does the airflow mode link set operate smoothly?	Yes	Go to the next step.
13		No	Replace the airflow mode link set, or airflow mode door, then perform the repair completion verification. (See A/C UNIT REMOVAL/INSTALLATION [(US)] .) (See A/C UNIT DISASSEMBLY/ASSEMBLY [(US)] .)
14	VERIFY DUCT INSTALLATION CONDITION Is the defroster duct installed to the position correctly and securely? (See DASHBOARD REMOVAL [(US)] .) (See DASHBOARD INSTALLATION [(US)] .) Are the defroster ducts installed properly? (See DASHBOARD REMOVAL [(US)] .) (See DASHBOARD INSTALLATION [(US)] .)	Yes	Inspect ducts for restriction, deformity, and air leakage, then perform the repair completion verification.
14		No	Install the incorrectly installed ducts properly, then perform the repair completion verification. (See DASHBOARD DISASSEMBLY/ASSEMBLY [(US)] .)
Repair completion verification	VERIFY THAT MALFUNCTION SYMPTOM DOES NOT RECUR AFTER REPAIR Is air discharged from vent? Does air flow from the vent while in each airflow mode?	Yes	Troubleshooting completed. Explain repairs to customer.
Repair completion verification		No	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW [(US)] .) If the CAN communication is normal, perform the diagnosis from Step 1.