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Service bulletins for the 2020 Mazda Mazda3

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

726 on file from NHTSA, as of 2026-10-19.

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Only bulletins with component: Heating and air conditioning are shown. Show all

Bulletins, newest first
SA-012-232023-04-04. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM; VISIBILITY. Some customers may report an odor or water in the HVAC system and upon inspection, the cabin air filter may be found to be wet.
07-004-22b2023-01-05. Service bulletin. ELECTRICAL SYSTEM; VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM. Some customers may complain the A/C blows warm. This may be caused by one of two things. Cause 1: After accelerating in hot weather, the A/C blows warm air for a longer time than other models. This is caused by improper control software of the PCM not allowing the A/C compressor to resume properly after acceleration. During a hard acceleration above a certain throttle level opening, the PCM stops the A/C compressor operation for better acceleration. It then resumes the compressor operation after the acceleration. To eliminate this concern, the control software of the PCM has been modified. Cause 2: Insufficient cooling performance at ambient temperature of around 68 °F (20 °C) in daytime. This is caused when both the ambient temperature and the cabin temperature are at around 20 °C (68 °F), auto A/C set at around 20 °C (68 °F) may not cool down the cabin temperature properly. To eliminate this concern, control software of the dash-electrical supply unit (Dash-ESU) has been modified.
SA-074-222022-12-02. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM; ELECTRICAL SYSTEM. Some customers may complain the HVAC system not maintaining the correct temperature or the ambient (outside) temperature reading incorrectly. This is caused by a failure in the ambient temperature sensor. To correct this issue, the ambient temperature sensor has been modified.
SA-072-222022-12-02. Service bulletin. ELECTRICAL SYSTEM; VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM. Customers may complain about the HVAC system is not blowing air and/or excessive noise from HVAC system.
07-006-20-37582021-01-05. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE:SOFTWARE; ENGINE AND ENGINE COOLING; EQUIPMENT:APPLIANCE:AIR CONDITIONER. Some customers may complain that after accelerating in hot weather, the A/C blows warm air for a longer time than other models. This is caused by improper control software of the PCM not allowing the A/C compressor to resume properly after acceleration. To eliminate this concern, the control software of the PCM has been modified.
07-005-20-37452020-11-03. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT:APPLIANCE:AIR CONDITIONER; ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT ADAPTIVE/MOBILITY. Some customers may complain that the A/C blows warm air while idling after restarting a warm engine. This is caused by improper control software of the PCM not allowing the active air shutter to open properly, resulting in lower cooling performance at idle. To eliminate this concern, the control software of the PCM has been modified.
SA-065-202020-10-05. Service bulletin. ENGINE AND ENGINE COOLING; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); EQUIPMENT:APPLIANCE:AIR CONDITIONER. Some customer's may complain that the HVAC system only blows warm to cool air (not cold) after starting the vehicle and not moving right away. This may be caused by a closed Active Air Shutter (AAS). Under specific circumstances, the AAS has a “learning issue” where AAS is kept closed after startup even if the PCM requests it to be open. The shutters will open and work correctly as soon as the vehicle speed exceeds 6.25 MPH (10 KPH). NO DTC will be set when this happens.
SA-057-202020-08-05. Service bulletin. EQUIPMENT:APPLIANCE:AIR CONDITIONER. Some customers may complain that the HVAC system blows hot air on occasion (blows cold air, then hot air, then cold air again). The customer may notice that it is more pronounced when they first start driving the vehicle and/or when accelerating.
07-001-20-36602020-01-30. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT:APPLIANCE:AIR CONDITIONER. Some customers may experience one side (driver side or passenger side) blowing warmer air out of the vents with the same or very close temperature settings for both sides when using the A/C and no DTCs related to the air conditioner system are stored in memory. This is caused by the air mix doors stopping operation during cranking and not recovering until the ignition is turned off. To correct this concern, the control software of the Dash-Electrical Supply Unit (Dash-ESU) has been modified.
07-002-19-3616a2019-12-20. Service bulletin. EQUIPMENT; EQUIPMENT:APPLIANCE:AIR CONDITIONER; EQUIPMENT ADAPTIVE/MOBILITY. A musty/mildew type odor may come from the vents when the air conditioning (A/C) system is operating. It is most noticeable when the A/C is first turned ON. This odor is the result of mold growth in the A/C evaporator/cooling unit which is caused by condensation, dust, and pollen within the cooling unit. This condition is usually worse during high humidity conditions. “Mazda Air Cooling Coil Coating” is available to encapsulate the mold to reduce odors. If the product is properly applied, it can effectively reduce the musty/mildew odor for up to three years. NOTE: See parts information for Mazda Air Cooling Coil Coating and Kit part numbers.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.