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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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Bulletins, newest first
MT-003-212021-06-29. Service bulletin. VISIBILITY:POWER WINDOW DEVICES AND CONTROLS. Some vehicles may experience exterior trim heat damage when parked near a glass building. This may be caused by the suns reflection. If a building creates enough of a curve with a series of flat windows, which act like mirrors, the reflections all converge at one point, focusing and concentrating the light onto the street below.
09-019-21-38132021-06-29. Service bulletin. FUEL SYSTEM, DIESEL:STORAGE:TANK ASSEMBLY. Some vehicles may exhibit a deformed fuel-filler lid panel (1) attached to the fuel-filler lid box, resulting in a poor appearance. This concern is caused by the lid box not having enough water drainage capability which leads to the accumulation of water inside it. The water then freezes in cold weather and expands or the inner side of the lid panel absorbs the water and swells from long exposure, deforming the lid panel. To eliminate this concern, the shape of the fuel-filler lid box has been modified to have better drainage capability and a modified fuel-filler lid panel service part has been established for less water absorbance.
09-018-21-37962021-06-29. Service bulletin. STRUCTURE. Some vehicles may exhibit that the liftgate interferes with the rear bumper when closed forcefully, resulting in damaged paint on the rear bumper. Due to variations of the clearance between the liftgate and the rear bumper, the bottom edge of the liftgate may overrun the rear bumper. To correct this concern, the following steps have been taken: Phase 1 - The hardness of stop rubbers on the liftgate has been modified for VINS greater than JM1BP*****300045 (produced after June 16, 2020). Phase 2 - A cushioning pad has been added to the hollow part in the liftgate weatherstrip (in addition to Phase 1 modification) for VINS greater than JM1BP*****313227 (produced after October 2, 2020)
09-012-21-3801a2021-06-29. Service bulletin. ELECTRICAL SYSTEM; LATCHES/LOCKS/LINKAGES; ENGINE AND ENGINE COOLING. Some customers may experience all of following symptoms: The door lock/unlock operation will not work using the remote transmitter button. The door lock/unlock operation will not work using the door lock/release touch sensor. The engine will not start using the ignition switch. This is caused when excess load is applied to the remote transmitter and the electrical terminals in it may be deformed, causing poor contact with the battery. To eliminate this concern, the structure in the remote transmitter has been modified to reduce the deformation of the electrical terminals.
04-003-21-38102021-06-29. Service bulletin. SERVICE BRAKES; EQUIPMENT ADAPTIVE/MOBILITY. Some customers may complain about the following braking concerns when coming to a stop while following a vehicle ahead using Mazda Radar Cruise Control with Stop and Go function (MRCC). Harder braking at slow speeds just before a complete stop. Before coming to a complete stop, the vehicle creeps towards the vehicle ahead and Depress Brake Pedal warning message may appear in the instrument cluster. This is caused by improper control software of the DSC HU/CM. To eliminate this concern, the control software of the DSC HU/CM has been modified.
SA-034-212021-06-03. Service bulletin. EQUIPMENT. When performing vehicle services such as control unit software update, control unit registration/activation, CMU log data retrieval, etc., always use the DCA8000 OR GR8 battery charger SST to maintain battery voltage.
SA-036-212021-06-03. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; LANE DEPARTURE; EXTERIOR LIGHTING; FORWARD COLLISION AVOIDANCE. Some vehicles may have one of the following DTCs stored in memory along with a system status notice on the Multi-information display OR display a system status notice with no DTC: C1001:92 - Forward sensing camera (FSC) poor field of view [Gen 6 vehicles], B14F0:92 - General temporary failure in forward sensing camera (FSC) [Gen 7 vehicles build on or before March 2, 2019], No DTC - Gen 7 vehicles built after March 2, 2019, DTC C1001:92 or B14F0:92 set as a past record for low visibility of the Forward Sensing Camera (FSC). It does not mean there is an actual FSC defect. In some cases the customer may have a concern with the Lane Departure Warning System (LDWS) and/or High Beam Control system (HBC). In other cases this DTC might be found without a related customer concern.
SA-012-21e2021-06-03. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT ADAPTIVE/MOBILITY. MAZDA CONNECTED SERVICES - FREQUENTLY ASKED QUESTIONS (FAQ): Index: General Questions, Setup and Getting Started, Registration / Enrollment, WI-FI General Information, WI-FI How-To, WI-FI Trial Period, Interacting With The App, Service Issues, Troubleshooting, Reception Level Inspection, Dealer Processes, Conditions for Remote Engine Start Will Not Function, Conditions for Remote Engine Start Function Will turn engine OFF, Educational Videos, Resources
SA-013-21e2021-06-03. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT ADAPTIVE/MOBILITY; EXTERIOR LIGHTING. Some customers may complain about any of the following: Infotainment Center Display does not provide the Authorization Code during the MyMazda App Connected Vehicle enrollment (and Software Update Error message on 2020 Mazda3 only). Remote function(s) inoperative. Engine Start / Stop, Door Lock / Unlock, Lights ON / OFF, MAZDA CONNECT connected vehicle reception strength icon shows "X" or " ".
SA-032-212021-06-03. Service bulletin. POWER TRAIN. There have been warranty claims submitted for growling or bearing whine noise in differentials, transfer units and transmissions where the source of the noise was a wheel bearing. This misdiagnosis can lead to multiple repair attempts, warranty debits, and additional inconvenience and/or cost to the customer. To reduce the chance of this occurring, please follow the steps outlined in the repair procedure.
SA-038-212021-06-02. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; ENGINE AND ENGINE COOLING. When the body control module (BCM) has been replaced or reprogrammed and the software is updated to the file names shown below, DTC U2050:55-BCM (Activation of remote control not implemented) may be stored in memory without any warning indication for the driver.
SA-031-212021-06-02. Service bulletin. ENGINE AND ENGINE COOLING. A new cylinder head assembly for service parts has been newly established for SKYACTIV-G 2.5 with cylinder deactivation when replacement is needed. Valves, valve springs, valve spring seats, and cotters (IN/EX) are included in the new assembly. DUE TO A SUPPLY ISSUE FOR CYLINDER HEADS, GASKET SETS, AND PARTIAL ENGINE, PLEASE CONTACT HOTLINE FOR REPAIR GUIDANCE.
SA-030-212021-06-02. Service bulletin. EQUIPMENT. Auxiliary key blank cutting procedure: There are currently 2 methods for cutting a new auxiliary key blank. A. Auxiliary Key Trace Cut Method, B. Auxiliary Key Code Cut Method
SA-004-21a2021-06-02. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT ADAPTIVE/MOBILITY. When the Telematics Control Unit (TCU) replacement is necessary due to a failure, use MDARS to activate the new TCU after replacement. Use the information in this service alert to initialize the new TCU until the procedure on MGSS is updated. CAUTION: If TCU activation is not performed, connected vehicle functions will not operate. This will have a negative impact on the customer because they will need to return to the dealer for repairs.
SA-003-21b2021-06-02. Service bulletin. FORWARD COLLISION AVOIDANCE; VEHICLE SPEED CONTROL; EQUIPMENT ADAPTIVE/MOBILITY. Some customers may complain about the following symptoms occurring when driving without anything ahead (no metallic object reflects the radar wave such as a vehicle ahead, an oncoming vehicle, a road sign or a guard rail). While using Mazda Radar Cruise Control (MRCC), the MRCC cancels by itself. NOTE: The customer may misinterpret MRCC cancellation as unintended braking. MRCC cancellation feels the same as the steering wheel cancel button being pressed or the brake pedal being tapped.
MT-002-212021-06-01. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. When programming a key or installing a Genuine Mazda Accessory Remote Engine Start system, you may encounter programming difficulty. This may be caused by a customer installed aftermarket decorative trim and/or cover on the START/STOP ENGINE button. The aftermarket accessory may create electrical interference, which may interfere with programming.
MT-001-212021-06-01. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING; EQUIPMENT. If you encounter any type of electrical concern (e.g, dead battery, engine no start, DTC(s) stored...), interview the customer before proceeding with normal Workshop Manual diagnosis. Aftermarket devices may be the cause of the electrical concern. Ask the customer if any aftermarket devices have been installed.
09-015-21-38052021-06-01. Service bulletin. ELECTRICAL SYSTEM; LATCHES/LOCKS/LINKAGES. Some CX-5 customers may find that the liftgate does not close when pressing the power liftgate (PLG) rear switch (A) located on the interior liftgate trim. This may be caused by PLG switch corrosion. Water from condensation may drip onto the switch connector and cause corrosion. To eliminate this concern, the PLG rear switch has been modified with a waterproof connector. Some Mazda3 customers may complain that the vehicle door locking system does not work when the door lock switch on the liftgate interior trim is pressed. DTC B11C4:23 (BCM - liftgate lock switch circuit malfunction) may be stored. This may be caused during a high pressure car washer. Water may enter through the rear center brand emblem base component and drip onto the switch connector causing corrosion. NOTE: The rusted connector may also cause a battery drain. To eliminate this concern, the rear center brand emblem base has been modified to prevent from water entry.
SA-013-21d2021-05-04. Service bulletin. ELECTRICAL SYSTEM. IMPORTANT NOTE: Some 2020 Mazda3 vehicles may have incorrect infotainment software version 10042 installed. The incorrect software will cause MyMazda App Connected Vehicle enrollment errors. Go to SSPC1. Some customers may complain about any of the following: Infotainment Center Display does not provide the Authorization Code during the MyMazda App Connected Vehicle enrollment (and Software Update Error message on 2020 Mazda3 only). Remote function(s) inoperative. Engine Start / Stop, Door Lock / Unlock, Lights ON / OFF
SA-029-212021-05-04. Service bulletin. EQUIPMENT. APPLE CARPLAY / ANDRID AURO FREQUENTLY ASKED QUESTIONS (FAQ) The following vehicles are not equipped with Apple CarPlay™ / Android Auto™, but it can be activated using MDARS. See Activation instructions on MGSS -> Infotainment -> MAZDA CONNECT Updates -> Apple Carplay / Android Auto MDARS Activation Instructions
SA-003-21a2021-05-04. Service bulletin. EQUIPMENT. Some customers may complain about the following symptoms occurring when driving without anything ahead (no metallic object reflects the radar wave such as a vehicle ahead, an oncoming vehicle, a road sign or a guard rail). While using Mazda Radar Cruise Control (MRCC), the MRCC cancels by itself. When MRCC is not in use, Safety and Driver Support Systems Temporarily Disabled. Front Radar Obscured. message appears in the instrument cluster / Remove dirt on the front radar sensor message appears in the center display and related i-ACTIVSENSE functions stop working.
09-012-21-38012021-05-04. Service bulletin. ELECTRICAL SYSTEM. Some customers may experience all of following symptoms: The door lock/unlock operation will not work using the remote transmitter button. The door lock/unlock operation will not work using the door lock/release touch sensor. The engine will not start using the ignition switch. This is caused when excess load is applied to the remote transmitter and the electrical terminals in it may be deformed, causing poor contact with the battery. To eliminate this concern, the structure in the remote transmitter has been modified to reduce the deformation of the electrical terminals.
01-004-21-3773a2021-05-04. Service bulletin. ENGINE AND ENGINE COOLING. Some vehicles may have the check engine light on with DTC P0524:00 or P055F:00 stored in memory. Contamination in the engine oil may cause the engine oil solenoid valve to become stuck, resulting in improper operation of the oil pump and improper oil pressure. DTC P0524:00 (Engine oil pressure too low), DTC P055F:00 (Engine oil pressure malfunction). The control software of the PCM has been modified to eliminate this concern. In addition, the production process has been modified to reduce contamination in the engine oil solenoid valve, oil pump, spacer and oil filter.
01-002-21-3767a2021-05-04. Service bulletin. ENGINE AND ENGINE COOLING. Some vehicle may exhibit a tapping noise from the engine during idling; etc., and synchronized to the engine rpm. The tapping noise may be caused by the switchable hydraulic lash adjuster (HLA), which may not work properly due to air bubbles accumulated in the oil passage in it. To eliminate this concern, the switchable HLA has been modified for increased oil supply to reduce air bubbles in the oil passage. NOTE: The switchable HLA can be pressed down with a finger if air bubbles have accumulated in it.
SA-012-21d2021-04-26. Service bulletin. EQUIPMENT. MAZDA CONNECTED SERVICES - FREQUENTLY ASKED QUESTIONS (FAQ): Index: General Questions, Setup and Getting Started, Registration / Enrollment, WI-FI General Information, WI-FI How-To, WI-FI Trial Period, Interacting With The App, Service Issues, Troubleshooting, Reception Level Inspection, Dealer Processes, Conditions for Remote Engine Start Will Not Function, Conditions for Remote Engine Start Function Will turn engine OFF, Educational Videos, Resources

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