2021 Mazda MAZDA3 Technical Service Bulletins

634 technical service bulletins (TSBs) are on record for the 2021 Mazda MAZDA3. TSBs are notes manufacturers send to dealers about repair procedures for issues seen in the field. They are not recalls and do not by themselves mean a vehicle has a fault.

• 11027024Dec 5, 2025Engine. SSPD8 - Check Engine Light ON with DTC P0126:00 - WARRANTY EXTENSION For certain 2018-2025MY CX-5, 2019-2023MY Mazda3, 2019-2022MY CX-3, 2018-2021MY Mazda6, 2020-2023MY CX-30 that are equipped with the suspected coolant control valve, the warranty coverage for specific repair of the fail-safe thermostat is extended to: 15 years (180 months) or 150,000 miles (240,000 km) whichever comes first, from the original…
• 11027023Dec 5, 2025Engine. SSPD8 - Check Engine Light ON with DTC P0126:00 - WARRANTY EXTENSION For certain 2018-2025MY CX-5, 2019-2023MY Mazda3, 2019-2022MY CX-3, 2018-2021MY Mazda6, 2020-2023MY CX-30 that are equipped with the suspected coolant control valve, the warranty coverage for specific repair of the fail-safe thermostat is extended to: 15 years (180 months) or 150,000 miles (240,000 km) whichever comes first, from the original…
• 11026906Dec 4, 2025Body and structure. Some customers may experience that the fuel lid and charge lid do not lock or unlock during door lock/unlock operation. This is caused by: Improper dimensional accuracy of the lid actuator lock mechanism Incomplete control logic in the R-ESU software To eliminate this concern: The mold design of the lid actuator was modified. The control software of the R-ESU was revised.
• 11026901Dec 4, 2025Engine. Some customers may experience a check engine light ON with DTC P0126:00 (Thermostat stuck open) and one or more of the following symptoms: Engine takes longer to warm up. Engine temperature gauge fluctuates. Low coolant temperature indicator (blue) light stays on longer or turns on while driving. Poor heater performance, especially at idle.
• 11026354Nov 27, 2025Transmission and drivetrain. When inspected, the differential or PTO oil is dark or black. This is considered normal and NO repair should be performed. During production, differential ring and pinion gears receive a manganese phosphate coating (commonly referred to as black oxide). This coating forms a porous, oil-retentive surface that improves boundary lubrication and reduces adhesive wear during initial contact cycles. Designed as a…
• 11026353Nov 26, 2025Brakes. Some vehicles exhibit brake related concerns such as brake noise, brake judder or brake dragging. If you encounter a customer complaint for any one of these symptoms, refer to the following information to understand why symptoms may occur, and to better assist the customer in resolving their specific brake concern. NOTE: Before following this Service Alert repair procedure, ensure published TSBs in MGSS have been…
• 11026099Nov 20, 2025Other or unknown, Body and structure. Some customers may experience that after the doors are locked and the Fuel Door Lock Delay with MAZDA CONNECT has passed (default setting is 90 seconds), the fuel-filler lid does not lock, but can be opened when pressed. NOTE: The fuel-filler lid does not lock immediately after the doors are locked, but after the time set in the Fuel Door Lock Delay (0, 30, 60, 90, and 120 seconds).
• 11026347Nov 19, 2025Wheels. 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.
• 11026350Nov 8, 2025Suspension, Steering, Transmission and drivetrain, Wheels. Noise, Vibration, and Harshness (NVH) Diagnostic Guidelines Diagnostic Guidelines When diagnosing NVH concerns, it is essential to first classify the issue into one of three primary categories: Noise, Vibration, or Harshness. Many customer complaints may involve overlapping symptoms, such as both noise and vibration, so identifying the dominant characteristic is critical. Once the primary symptom is determined…
• 11026351Nov 6, 2025Engine, Transmission and drivetrain. Some customer's might state that they notice fluid or oil leaking/dripping on the ground when the vehicle is parked. For this concern, inspect the vehicle for any trace of a fluid or oil leak and use the following examples as a guide to determine if it is severe enough to require a repair, or just to clean the area and monitor it at the next service. Examples of residue or seepage that may not be considered a leak…
• 11024989Oct 31, 2025Body and structure. Some customers may notice water in the trunk after a car wash or heavy rain. This may be caused by insufficient sealing performance of the trunk lid weatherstrip. Due to improper installation of weatherstrips, the lip of the weatherstrip may lean toward the inside of the trunk, resulting in insufficient sealing performance. To eliminate this concern, the length of the trunk lid weatherstrip has been extended 14 mm…
• 11025007Oct 25, 2025Engine. SPECIAL SERVICE PROGRAM - SSPD5 - WARRANTY EXTENSION - MULTI-MODEL - VALVE STEM SEALS CLASS ACTION In conjunction with a Class Action Settlement, Mazda Motor Corporation has decided to conduct an extension of the Engine powertrain warranty related to excessive oil consumption.
• 11025006Oct 25, 2025Engine. SPECIAL SERVICE PROGRAM - SSPD5 - WARRANTY EXTENSION - MULTI-MODEL - VALVE STEM SEALS CLASS ACTION In conjunction with a Class Action Settlement, Mazda Motor Corporation has decided to conduct an extension of the Engine powertrain warranty related to excessive oil consumption.
• 11025005Oct 25, 2025Engine. SPECIAL SERVICE PROGRAM - SSPD5 - WARRANTY EXTENSION - MULTI-MODEL - VALVE STEM SEALS CLASS ACTION In conjunction with a Class Action Settlement, Mazda Motor Corporation has decided to conduct an extension of the Engine powertrain warranty related to excessive oil consumption.
• 11024991Oct 24, 2025Electrical system, Other or unknown. Some customers may experience rear subwoofer audio sound pauses intermittently at high volume levels. When the volume level is lowered, the subwoofer audio sound resumes. The actual volume level may vary depending on the audio source. If the audio source consists of many low frequency (40 - 70 Hz) sounds, the concern may occur at volume level 35 or higher. This concern may be caused by improper audio amplifier…
• 11024994Oct 23, 2025Electrical system. The Mazda DCA-8000 is required for all warranty battery testing. If the Mazda DCA-8000 is not used, incorrect battery testing may result in unnecessary battery replacement. Use the following test procedures in this Service Bulletin to test Mazda vehicle batteries and to generate a Warranty Code. NOTE: A Warranty Code is required for warranty claim submission Battery Identification (Mazda batteries have 2 rating…
• 11024995Oct 17, 2025Body and structure. Some customers will report that their fuel door (AKA, fuel filler door, fuel lid, and fuel-filler lid) was stuck closed and would not open to refuel the vehicle. Follow the repair steps below unless the conditions outlined in TSB 09-007/25 - FUEL-FILLER LID PANEL IS DEFORMED for 2019-2025 Mazda3 and 2020-2025 CX-30 are present.
• 11025009Oct 8, 2025Electrical system, Other or unknown. 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.
• 11024996Oct 7, 2025Other or unknown. Customers having MAZDA CONNECT concerns should have their vehicle repaired using the following repair procedure.
• 11024999Oct 2, 2025Electrical system. For improvement of electrical diagnosis, the SKYACTIV® Wiring Terminal Test Kits has been delivered all the dealers. The terminal test kit enables you: To check pin fit drag of all PCM terminals used in SKYACTIV® vehicles and compare suspect terminal drag with a known good terminal. To measure the voltage/resistance avoiding any terminal damage.
• 11023703Sep 30, 2025Other or unknown. 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 built on or before March 2, 2019] No DTC - Warning Message only [Gen 7…
• 11023702Sep 30, 2025Other or unknown. Interior parts made of resin have antistatic coating to prevent dust from sticking on the surfaces, and depending on the conditions of use, the antistatic components may crystallize slightly, giving an appearance of white stains on the surface.
• 11023700Sep 9, 2025Other or unknown, Electrical system. Mazda Connected Services - Frequently Asked Questions
• 11022742Aug 22, 2025Other or unknown, Body and structure. Some vehicles may experience exterior trim heat damage such (melted, separating, etc.) when parked near a glass building or Low-E windows. This may be caused by the sun's reflection. If a structure's windows create enough of a curve, the concave glass can focus the sun's rays onto a small area and acting like magnifiying glass direct the sunbeams into a hot pinpoint of light. This magnifcation of the sun's rays can…
• 11022725Aug 22, 2025Other or unknown, Engine, Exterior lighting, Electrical system. Some customers may complain about any of the following: 1. Infotainment Center Display does not provide the Authorization Code (OTP) during the MyMazda App Connected Vehicle enrollment. 2. Remote function(s) inoperative. Engine Start / Stop Door Lock / Unlock Lights ON / OFF Climate Control 3. MAZDA CONNECT connected vehicle reception strength icon shows "X" or " ".
• 11022717Aug 22, 2025Other or unknown, Electrical system. Some customers may experience a Connected Vehicle failure. The MyMazda App may display an Error Code. This document provides Error Code description and recovery information to assist with repairs.
• 11022718Aug 21, 2025Other or unknown, Electrical system. Customers having MAZDA CONNECT concerns should have their vehicle repaired using the following repair procedure.
• 11022624Aug 20, 2025Body and structure, Other or unknown. Some customers may notice water in the trunk after a car wash or heavy rain. This may be caused by insufficient sealing performance of the trunk lid weatherstrip. Due to improper installation of weatherstrips, the lip of the weatherstrip may lean toward the inside of the trunk, resulting in insufficient sealing performance.
• 11022738Aug 15, 2025Other or unknown. When replacing the MAZDA CONNECT remote tuner (RT) with a replacement tuner for any reason, a call must be made to inform SiriusXM of the existing Radio ID and the new/replacement SAT Radio ID as soon as possible to ensure the customer leaves the dealership with an active SAT radio.
• 11022762Aug 9, 2025Engine. SPECIAL SERVICE PROGRAM - SSPD5 - WARRANTY EXTENSION - MULTI-MODEL - VALVE STEM SEALS CLASS ACTION In conjunction with a Class Action Settlement, Mazda Motor Corporation has decided to conduct an extension of the Engine powertrain warranty related to excessive oil consumption.
• 11022763Aug 7, 2025Engine. SPECIAL SERVICE PROGRAM - SSPD5 - WARRANTY EXTENSION - MULTI-MODEL - VALVE STEM SEALS CLASS ACTION In conjunction with a Class Action Settlement, Mazda Motor Corporation has decided to conduct an extension of the Engine powertrain warranty related to excessive oil consumption.
• 11022758Aug 7, 2025Engine. SPECIAL SERVICE PROGRAM - SSPD5 - WARRANTY EXTENSION - MULTI-MODEL - VALVE STEM SEALS CLASS ACTION In conjunction with a Class Action Settlement, Mazda Motor Corporation has decided to conduct an extension of the Engine powertrain warranty related to excessive oil consumption.
• 11022726Aug 6, 2025Electrical system, Other or unknown. Some vehicles may show “TSR system performance is reduced. Navigation Data Unavailable" or "Check Navigation SD Card" in the meter while driving.
• 11022618Aug 1, 2025Other or unknown. Some vehicles may experience a sunvisor that does not stay in the fully retracted position (as shown below). The left and/or right side sunvisor may lower slightly due to its own weight. The part where the sunvisor connects is broken, so the spring cannot hold the sunvisor in the fully retracted position. To eliminate this concern, the stay holder and spring holder have been reinforced.
• 11021389Jul 29, 2025Other or unknown. Some vehicles may exhibit that the glass run channel of the front door interferes with the rear door garnish. Since the front door glass run channel is not fixed to the door strongly enough for the following situations, cycles of door operation may result in interference and lead to damage on the seal rubber at the rear door.
• 11021499Jul 14, 2025Other or unknown, Exterior lighting, Engine. Some customers may complain about any of the following: 1. Infotainment Center Display does not provide the Authorization Code (OTP) during the MyMazda App Connected Vehicle enrollment. 2. Remote function(s) inoperative. Engine Start / Stop Door Lock / Unlock Lights ON / OFF Climate Control 3. MAZDA CONNECT connected vehicle reception strength icon shows "X" or " ".
• 11021498Jul 14, 2025Other or unknown. Mazda Connected Services - Frequently Asked Questions (FAQ)
• 11020039Jun 19, 2025Other or unknown. Some customers may complain about a noisy HVAC blower motor or odor after a cabin air filter replacement. Foreign debris on the blower motor after servicing the cabin air filter may be the cause. During the removal of the cabin air filter, foreign debris (leaves, dust, dirt....ect.) may fall on the blower motor causing a fluttering type noise or odor.
• 11020038Jun 18, 2025Other or unknown. 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.
• 11020037Jun 6, 2025Engine. A tapping/rattling noise may be noticed from the valve train area. This operating condition can occur on new vehicles which have been delivered to Mazda dealers (due to loading and unloading from transport trucks or customers moving their vehicles in and out of their garages to wash the vehicle, etc.). This condition may also occur if the engine is not allowed to warm up after multiple cold starts.
• 11020035Jun 3, 2025Electrical system. The Mazda DCA-8000 is required for all warranty battery testing. If the Mazda DCA-8000 is not used, incorrect battery testing may result in unnecessary battery replacement. Use the following test procedures in this Service Bulletin to test Mazda vehicle batteries and to generate a Warranty Code. NOTE: A Warranty Code is required for warranty claim submission Battery Identification (Mazda batteries have 2 rating…
• 11019180May 16, 2025Other or unknown. Mazda Navigation Live Traffic information is available on the following 2 systems. SiriusXM® 3 Yr Traffic and Travel Link* Mazda Online Navigation* The table below provides Setting information for both systems. See APPLICABLE MODEL(S)/VINS above to determine how vehicles are equipped. NOTE: When selecting Navigation, data upload may take a few seconds. This is a normal function.
• 11019179May 16, 2025Other or unknown, Electrical system, Exterior lighting, Engine. Some customers may complain about any of the following: 1. Infotainment Center Display does not provide the Authorization Code (OTP) during the MyMazda App Connected Vehicle enrollment. 2. Remote function(s) inoperative. Engine Start / Stop Door Lock / Unlock Lights ON / OFF Climate Control 3. MAZDA CONNECT connected vehicle reception strength icon shows "X" or " ".
• 11019178May 16, 2025Other or unknown. Frequently Asked Questions (FAQ) for Mazda Connected Services.
• 11019177May 16, 2025Other or unknown. Customers having MAZDA CONNECT concerns should have their vehicle repaired using the following repair procedure.
• 11019160May 16, 2025Visibility (wipers, defrost, mirrors). Some vehicles may exhibit wiper blade contact with the A-pillar trim, with or without a chattering noise. This condition may be caused by worn or contaminated wiper blades. It can also be caused by bent wiper arms, or loose wiper arm retaining nuts due to improper handling. Improper handling occurs when pulling on or forcing the wiper arms.
• 11017703Apr 29, 2025Other or unknown. CSP13 - CUSTOMER SERVICE PROGRAM - MAZDA CONNECT INFOTAINMENT SYSTEM LIMITED WARRANTY EXTENSION. As a result of a Mazda Connect Infotainment Class Action settlement, Mazda Motor Corporation has decided to implement a Customer Service Program (CSP13). The coverage and terms for vehicles are listed below in this Dealer email and in attached documentation.
• 11017699Apr 25, 2025Other or unknown. 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…
• 11017697Apr 16, 2025Other or unknown. 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.
• 11017481Apr 8, 2025Body and structure. Some customers may complain that it is difficult to open/close the fuel-filler lid when pressed. This is caused by production variances, where if there is an excess gap (3) between the fuel-filler lid panel (1) and the fuel-filler box hinge (2), the operation stroke may be larger than designed and result in a difficult to lock/unlock operation of the fuel-filler lid lock actuator.

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