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.

AMOUNT OF AIR BLOWN FROM VENTS DOES NOT CHANGE (AUTO A/C) (US) 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	INSPECT TO SEE WHETHER MALFUNCTION IS IN BLOWER UNIT OR ELSEWHERE Switch the ignition ON (engine off or on). Turn the airflow volume control switch on. Recirculate air inside the vehicle. Does the blower motor rotate?	Yes	Go to the next step.
2		No	Go to Step 4.
3	INSPECT BLOWER UNIT INTAKE VENT Is blower unit intake vent restricted?	Yes	Remove obstruction, then perform the repair completion verification.
3		No	Inspect if there are any obstruction in the A/C unit passage, then perform the repair completion verification.
4*	INSPECT BLOWER MOTOR POWER SUPPLY CIRCUIT FOR SHORT TO GROUND AND OPEN CIRCUIT Inspect the power supply circuit for an open circuit and short to ground. (See CIRCUIT INSPECTION .) Is the circuit normal?	Yes	Go to the next step.
4*		No	Repair or replace the malfunctioning location and perform the repair completion verification.
5	INSPECT TO SEE WHETHER MALFUNCTION IS IN BLOWER MOTOR OR ELSEWHERE Switch the ignition off. Disconnect the negative battery terminal. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION [(US)] .) Inspect the blower motor. (See BLOWER MOTOR INSPECTION .) Is the blower motor normal?	Yes	Go to the next step.
5		No	Replace the blower motor, then perform the repair completion verification. (See BLOWER MOTOR REMOVAL/INSTALLATION [(US)] .)
6	INSPECT BLOWER MOTOR CONTROL CIRCUIT FOR OPEN CIRCUIT Inspect the applicable circuit for open circuit. (See CIRCUIT INSPECTION .) Is the circuit normal?	Yes	Go to the next step.
6		No	Repair or replace the malfunctioning location and perform the repair completion verification.
7	INSPECT BLOWER MOTOR CONTROL CIRCUIT FOR SHORT TO GROUND Inspect the applicable circuit for a short to ground. (See CIRCUIT INSPECTION .) Is the circuit normal?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning location and perform the repair completion verification.
8	INSPECT BLOWER MOTOR CONTROL CIRCUIT FOR SHORT TO POWER SUPPLY Inspect the applicable circuit for a short to power supply. (See CIRCUIT INSPECTION .) Is the circuit normal?	Yes	Go to the next step.
8		No	Repair or replace the malfunctioning location and perform the repair completion verification.
Repair completion verification	VERIFY THAT MALFUNCTION SYMPTOM DOES NOT RECUR AFTER REPAIR Is air discharged from vent?	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, replace the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION (AUTO A/C) (US) .)