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.

NO WARM AIRFLOW FROM VENT (MANUAL A/C) DIAGNOSTIC PROCEDURE

Step	Inspection		Action
1	VERIFY DTCs Perform the DTC inspection for the following modules. (See DTC INSPECTION .) PCM Dash-electrical supply unit Is a DTC displayed?	Yes	Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [PCM (SKYACTIV-G (US))] .) (See DTC TABLE [DASH-ELECTRICAL SUPPLY UNIT (US)] .)
1		No	Go to the next step.
2	VERIFY AIRFLOW CONDITION Switch the ignition ON (engine off or on). Turn the airflow volume control switch on. Does air flow from the vents 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 (MANUAL A/C) (US) .)
3	VERIFY IF MALFUNCTION IS CAUSED BY ENGINE OVERCOOLING Using the M-MDS, display the PCM PID [ECT]. (See PID/DATA MONITOR INSPECTION .) Switch the ignition ON (engine off or on) and warm up the engine while idling. Is the monitor value 80°C or more?	Yes	Go to the next step.
3		No	Go to the following malfunction symptom item. (See COOLING SYSTEM CONCERNS-RUNS COLD [SKYACTIV-G] .)
4	VERIFY IF MALFUNCTION IS CAUSED BY LACK OF ENGINE COOLANT Inspect the engine coolant amount. (See ENGINE COOLANT LEVEL INSPECTION [SKYACTIV-G (VIN L (US))] .) (See ENGINE COOLANT LEVEL INSPECTION [SKYACTIV-G (VIN M (US))] .) Is the engine coolant amount normal?	Yes	Repair or replace the heater core and go to the repair completion verification. (See A/C UNIT DISASSEMBLY/ASSEMBLY (US) .)
4		No	Add engine coolant and verify that there is no leakage in the engine coolant passage. (See ENGINE COOLANT REPLACEMENT [SKYACTIV-G (VIN L (US))] .) (See ENGINE COOLANT REPLACEMENT [SKYACTIV-G (VIN M (US))] .) If there is any malfunction Repair or replace the malfunctioning location and perform the repair completion verification.
Repair completion verification	VERIFY THAT MALFUNCTION DOES NOT RECUR AFTER REPAIRS Does warm air flow when the airflow temperature setting is MAX HOT?	Yes	Troubleshooting completed. (Explain repair contents to the customer)
Repair completion verification		No	Refer to the CAN (controller area network) 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.