2021 Mazda CX-9 problems, complaints & recalls

2021 Mazda CX-9 recalls (1)

• Recall 21V750000Sep 27, 20218,648 vehicles
  SEAT BELTS:REAR/OTHER · SEATS:MID/REAR ASSEMBLY

  Mazda North American Operations (Mazda) is recalling certain 2020-2021 CX-9 vehicles equipped with 60/40 split bench second-row seats. The left-side second-row seat may unexpectedly slide forward during a crash. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 210, "Seat Belt Assembly Anchorages."

  Risk: A seat that slides forward during a crash can transfer excessive force onto a belted occupant, increasing their risk of injury.

  Remedy: Dealers will replace the internal parts of the affected second-row seats, free of charge. Owner notification letters were mailed November 4, 2021. Owners may contact Mazda customer service at 1-800-222-5500, Option 4. Mazda's number for this recall is 5221I.

Recent 2021 Mazda CX-9 complaints

Excerpts of the newest owner complaints, lightly cleaned of personal details. Complaints are unverified owner reports.

1. Filed Sep 12, 2026TXDriver Assistance & Safety TechAcceleration & Cruise ControlTransmission & Drivetrain

   I entered the interstate normally, with no issues accelerating or merging. While driving at approximately 70 mph, in traffic, all three warning messages appeared on the instrument cluster at the same time: “Smart Brake System Malfunction,” “Driver Attention Alert System Malfunction,” and “Forward Smart City Brake Support Malfunction.” At the same moment, the vehicle began to lose speed. I pressed the accelerator pedal firmly. The speed continued to decrease instead of…

   NHTSA complaint #11763863 · source
2. Filed Aug 27, 2026ILWheels & Tires

   On a high-speed highway (Route 14), the vehicle suffered a sudden flat tire/air loss event, forcing an emergency pull-off onto a narrow shoulder with 65 mph traffic. Subsequent inspection revealed the failed tire and the rest of the set were manufactured in late 2007 (DOT code 4907). These 19-year-old tires were installed by a professional tire shop despite being far beyond their safe service life. Component/System Failed: Tires (Set of 4). Tire Size: 255/50 R20 (Vredestein…

   NHTSA complaint #11760004 · source
3. Filed Aug 10, 2026IACrashTowedEngineAcceleration & Cruise ControlTransmission & Drivetrain

   The vehicle was parked stationary in the driveway with the engine running for 3-5 minutes with the A/C on. The vehicle then accelerated forward into my garage causing damage. Once I entered the vehicle, both the dash and shifter displayed park. Current TCU system internal failures have been reported from the pulling of data from Mazda.

   NHTSA complaint #11755863 · source
4. Filed Jul 23, 2026RIEngine

   1) What component or system failed or malfunctioned: On 6/12/2026 While drive on the highway with our daughter in the car and we experienced a high speed stall. The engine failed and we lost power. We barely got the car of the highway and coasted into a parking lot. 2) Life threating for Father, Mother and daughter and other drivers on the highway. 3) The Mazda dealer stated they were unable to reproduced problem. The diagnostic report showed few random misfired on two…

   NHTSA complaint #11752508 · source
5. Filed Jul 12, 2026VAEngine

   This complaint refers to Mazda and it's dealer refusal to properly execute the warranty work under the SSPD5 Valve Stem Seal Class Action Campaign and does not follow the Court's approval of the final Settlement Agreement. I assert that Mazda and it's dealer are not following the SSPD5 repair procedures. 1. I have documentation and complaints going back to Dec-2023 with this particular dealer that I have experienced low level oil consumption within the 7,500 mile oil change…

   NHTSA complaint #11749820 · source
6. Filed Jun 18, 2026MAEngine

   Check engine light comes on and error P0303 comes on. Had an independent mechanic do the following and after each one, error P0303 still came on 1. Swap the ignition coils from 2 to 3 2. Swap spark plugs from 2 to 3 3. Swapped injectors 4. Compression test 5. Leak down test 6. Changed the spark plug, coil and injectors 7. Looked for vacuum leaks. Mechanic believes that it is related to the cracked cylinder head in the recall, MC-10232269-0001.pdf. My vehicle is just outside…

   NHTSA complaint #11745150 · source
7. Filed Dec 10, 2025AZCrashDriver Assistance & Safety Tech

   Backup camera shows three to four feet before red collision line is not accurate causing severe damage to my garage door.

   NHTSA complaint #11704278 · source
8. Filed Jun 5, 2025GATransmission & Drivetrain

   My vehicle is part of Mazda's 2021-2022 Mazda Valve Stem Seal Settlement. The dealership had yet to call me in for the repair of said valve seal repair as I was on a list. The settlement is suppose to extend out the powertrain warranty on the vehicle 2 years/24,000 to 7 years/84,000. My vehicle has 60,083 miles on it. One of the cylinders on my vehicle lost compression. The dealership and Mazda both say they will not cover the cost for repair as they only are covering things…

   NHTSA complaint #11665046 · source

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Source: U.S. National Highway Traffic Safety Administration (NHTSA) Office of Defects Investigation public data, as of Oct 11, 2026. Complaints are submitted by owners and are not verified by NHTSA or by us; a complaint does not prove a defect exists. View this vehicle on NHTSA.gov Methodology