Service bulletins for the 2020 Mazda Mazda6
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.
364 on file from NHTSA, as of 2026-10-19.
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Only bulletins with component: Engine are shown. Show all
| 00-001-22 | 2022-03-04. Service bulletin. POWER TRAIN; SERVICE BRAKES, HYDRAULIC; ENGINE AND ENGINE COOLING; STEERING. Mazda has developed factory recommended scheduled maintenance services that support all major vehicle systems. Mazda recommends dealers follow the scheduled maintenance tables as cited in the vehicle-specific workshop manual or owner's manual. Services performed outside of Mazda's factory scheduled maintenance are not recommended. These services are unnecessary and create unneeded expenses for your customers. |
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| 01-013-21-3753a | 2022-01-06. Service bulletin. ENGINE AND ENGINE COOLING. Coolant Leaks At Cylinder Head: Some vehicles may have coolant leaks at the cylinder head around the exhaust manifold (as shown below). There may be cracks at the stud bolt hole (1) or at the outside of the exhaust manifold (2). |
| SA-031-21c | 2022-01-05. Service bulletin. ENGINE AND ENGINE COOLING; POWER TRAIN. New Cylinder Head Assembly Established: 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. |
| SA-031-21c | 2021-11-01. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY. 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. Dealers can now utilize the Limited Parts Ordering (LPO) page on eMDCS to order the repair parts for 2.5L (with cylinder deactivation) and 2.5L turbo cylinder head repairs. There is no longer a need to contact hotline for part ordering. If there are any questions on part ordering or part status, contact the DAG group for assistance. |
| SA-031-21b | 2021-11-01. Service bulletin. ENGINE AND ENGINE COOLING; POWER TRAIN; EQUIPMENT. 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. |
| 01-013-21-3753 | 2021-10-31. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:MANIFOLD/HEADER/MUFFLER/TAIL PIPE; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT. Some vehicles may have coolant leaks at the cylinder head around the exhaust manifold (as shown below). There may be cracks at the stud bolt hole (1) or at the outside of the exhaust manifold (2). Cracks may be caused by: Deformation of the exhaust manifold during usage causing unexpected force to certain areas of the cylinder head. Residual stress generated during production in the cylinder head material may be greater than expected. The external force from the exhaust system when driving over bumps may cause unexpected force to certain areas of the cylinder head. To eliminate this concern, the design of the exhaust manifold gasket and the cylinder head has been modified to reduce the force on the cylinder head. |
| SA-047-21 | 2021-10-05. Service bulletin. ENGINE AND ENGINE COOLING. If you receive a customer concern about the CHECK ENGINE light coming on and DTC P3400 (cylinder deactivation system malfunction) stored, the cylinder deactivation oil control valve may be plugged with plastic debris from the oil filter wrapper. The debris may enter the center of the oil filter when poking a hole in the filter wrapper during removal, and then travel through the engine and plug the cylinder deactivation oil control valve. |
| MT-002-21 | 2021-10-02. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING. Ethanol is becoming a common additive in gasoline. Gasoline containing ethanol is likely available at your local gasoline station. Typical blends of ethanol include E10 and E85. E10: A blend of 10% ethanol and 90% gasoline, E85: A blend of 85% ethanol and 15% gasoline, All Mazda vehicles can run on gasoline containing up to 10% ethanol (E10) but only some 1999-2001 B3000 trucks can run on gasoline with more than 10% ethanol blended. E10 compatible vehicles: All Mazda vehicles. E85 compatible vehicles: 1999-2001 B3000 Mazda trucks with the 8th VIN digit is V. What if a customer puts E85 in there Mazda vehicle? Symptoms include: Rough Running, Lean Codes, Misfires and/or misfire codes, Lack of power, Poor fuel economy, Spark knock, Mechanical engine damage. |
| 07-003-21-3825 | 2021-10-02. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. Some vehicles may exhibit a squeaking noise from the blower motor while it is operating. This is caused by burrs that were not trimmed completely in the manufacturing process of the blower motor. To eliminate this concern, the manufacturing process of the blower motor has been modified to efficiently trim burrs. |
| 01-011-21-3800a | 2021-10-02. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; ENGINE AND ENGINE COOLING. Some customers may experience the CHECK ENGINE light ON with DTC P0126:00 (Thermostat stuck open) and one or more of the following symptoms: The engine takes longer to warm up, The engine temperature gauge fluctuates, The low coolant temperature indicator (blue) light stays on longer or comes on while driving, Poor heater performance, especially at idle. NOTE: Vehicles with SKYACTIV-G 2.5T are not applicable. Due to production variety of the failsafe thermostat integrated in the coolant control valve, engine coolant may enter into a dry hollow in the failsafe thermostat, resulting in unintended opening of the failsafe thermostat at lower temperatures (104-176 °F (40-80 °C)). To eliminate this concern, the production process of the coolant control valve has been modified. |
| SA-031-21a | 2021-09-03. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. 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. |
| 01-006-21-3779a | 2021-09-03. Service bulletin. ELECTRICAL SYSTEM:12V/24V/48V BATTERY; ENGINE AND ENGINE COOLING. This service bulletin provides testing and charging procedures in order to promote proper battery maintenance, to deliver new vehicles with fully charged batteries, and to reduce unnecessary battery replacement cost. For new vehicles in stock at the dealer, inspect and maintain the battery periodically according to the repair procedure. |
| 09-012-21-3801a | 2021-06-29. 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. |
| SA-031-21 | 2021-06-02. 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. |
| MT-002-21 | 2021-06-01. 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-001-21 | 2021-06-01. 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. |
| 01-004-21-3773a | 2021-05-04. 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. |
| 01-002-21-3767a | 2021-05-04. 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. |
| 01-011-21-3800 | 2021-04-26. Service bulletin. ENGINE AND ENGINE COOLING. Some customers may experience the CHECK ENGINE light ON with DTC P0126:00 (Thermostat stuck open) and one or more of the following symptoms: The engine takes longer to warm up, The engine temperature gauge fluctuates, The low coolant temperature indicator (blue) light stays on longer or comes on while driving, Poor heater performance, especially at idle. NOTE: Vehicles with SKYACTIV-G 2.5T are not applicable. Due to production variety of the failsafe thermostat integrated in the coolant control valve, engine coolant may enter into a dry hollow in the failsafe thermostat, resulting in unintended opening of the failsafe thermostat at lower temperatures (104-176 °F (40-80 °C)). To eliminate this concern, the production process of the coolant control valve has been modified. |
| SA-017-21a | 2021-04-06. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. CHECK ENGINE LIGHT ON WITH DTC P0126:00 AND ENGINE RUNNING COOLER THAN NORMAL / POOR HEATER PERFORMANCE / LOW ENGINE COOLANT TEMPERATURE (BLUE) LIGHT ON: Some customers may experience the CHECK ENGINE LIGHT ON with DTC P0126:00 (Thermostat stuck open) and one or more of the following symptoms: The engine takes longer to warm up. The engine temperature gauge fluctuates. The low coolant temperature indicator (blue) light stays on longer or comes on while driving. Poor heater performance, especially at idle. |
| SA-017-21 | 2021-03-03. Service bulletin. ENGINE AND ENGINE COOLING. Some customers may experience the CHECK ENGINE LIGHT ON with DTC P0126:00 (Thermostat stuck open) and one or more of the following symptoms: The engine takes longer to warm up. The engine temperature gauge fluctuates. The low coolant temperature indicator (blue) light stays on longer or comes on while driving. Poor heater performance, especially at idle. |
| 01-003-21-3776 | 2021-02-05. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING; EQUIPMENT. Some vehicles may experience the CHECK ENGINE LIGHT ON with DTC P2610 and P2507 stored in memory after engine start and room fuse 15A (A) removed. P2610:00: Instrument cluster internal engine off timer performance problem. P2507:00: PCM battery voltage low input |
| 01-002-21-3767 | 2021-02-05. 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. |
| 00-001-21-3768 | 2021-02-05. Service bulletin. STEERING; WHEELS; POWER TRAIN; ENGINE AND ENGINE COOLING. Mazda has developed factory recommended scheduled maintenance services that support all major vehicle systems. Mazda recommends dealers follow the scheduled maintenance tables as cited in the vehicle specific workshop manual or owner's manual. Services performed outside of Mazda's factory scheduled maintenance are not recommended. These services are unnecessary and create unneeded expenses for your customers. |
| SA-058-20c | 2021-01-06. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM. 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. NOTE: Cylinder head replacement requires MASH authorization. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.