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.

SWITCH/DIAL OPERATION DOES NOT RESPOND (AUTO A/C) DIAGNOSTIC PROCEDURE

Step	Inspection		Action
1	VERIFY MALFUNCTION DURING EACH SWITCH/DIAL OPERATION Do the related parts operate according to the switch/dial operation of the climate control unit?	Yes	Perform the repair completion verification.
1		No	If specific switch/dial operation does not respond Go to the next step. If all switch/dial operations do not respond Go to the following malfunction symptom item. (See ALL SWITCH/DIAL OPERATION DOES NOT RESPOND (AUTO A/C) (US) .)
2	VERIFY MALFUNCTIONING SWITCH/DIAL Is any one of the following climate control unit switch the one which does not respond to being operated? Steering warmer switch Seat warmer switch	Yes	Go to the applicable inspection. Steering warmer switch (See HEATED STEERING WHEEL CONTROL UNIT INSPECTION .) Seat warmer switch
2		No	Go to the next step.
3	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)] .)
3		No	Go to the next step.
4	VERIFY MALFUNCTIONING SWITCH/DIAL Is the switch which does not respond to being operated the rear window defogger switch?	Yes	Verify the body control module (BCM) DTCs. (See DTC INSPECTION .) If DTC is displayed: Repair the malfunctioning location according to the applicable DTC troubleshooting. (See DTC TABLE [BODY CONTROL MODULE (BCM) (US)] .) If DTC is not displayed: Replace the climate control unit, then perform the repair completion verification. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION (AUTO A/C) (US) .)
4		No	Go to the next step.
5	VERIFY MALFUNCTIONING SWITCH/DIAL Is any one of the following climate control unit switch/dials the one which does not respond to being operated? REC/FRESH switch Temperature control dial MODE switch AUTO switch SYNC switch DEFROSTER switch Power switch	Yes	Replace the climate control unit, then perform the repair completion verification. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION (AUTO A/C) (US) .)
5		No	Go to the next step.
6	VERIFY MALFUNCTION DURING AIRFLOW VOLUME CONTROL SWITCH OPERATION Is the switch which does not respond to being operated the climate control unit airflow volume control switch?	Yes	Go to the next step.
6		No	Go to Step 8.
7	DETERMINE IF MALFUNCTION IS CAUSED BY FRONT BLOWER MOTOR CIRCUIT MALFUNCTION OR FRONT CLIMATE CONTROL UNIT MALFUNCTION Is the airflow volume setting displayed normally in the display panel after operating the climate control unit airflow volume control switch?	Yes	Go to the following malfunction symptom item. (See AMOUNT OF AIR BLOWN FROM VENTS DOES NOT CHANGE (AUTO A/C) (US) .)
7		No	Replace the climate control unit, then perform the repair completion verification. (See (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION (AUTO A/C) (US) .).)
8	VERIFY MALFUNCTION DURING A/C SWITCH OPERATION Is the switch which does not respond to being operated the climate control unit A/C switch?	Yes	Go to the next step.
8		No	Perform the repair completion verification.
9	DETERMINE IF MALFUNCTION IS CAUSED BY A/C OPERATION CIRCUIT MALFUNCTION OR FRONT CLIMATE CONTROL UNIT MALFUNCTION Is [A/C] displayed in the display panel after operating the climate control unit A/C switch?	Yes	Go to the following malfunction symptom item. (See NO COOL AIR (AUTO A/C) (US) .)
9		No	Go to the next step.
10	VERIFY AMBIENT TEMPERATURE Is the ambient temperature - 5°C or less?	Yes	Normal (A/C does not turn on when ambient temperature is -5°C or less to protect A/C compressor)
10		No	Replace the climate control unit, then perform the repair completion verification. (See (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION (AUTO A/C) (US) .).)
Repair completion verification	VERIFY THAT MALFUNCTION SYMPTOM DOES NOT RECUR AFTER REPAIR Do the related parts operate according to the switch/dial operation of the climate control unit?	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.