Most common 2021 Mazda CX-9 problems
Share of the 40 complaints; one complaint can involve more than one system. "~" is the median mileage when the problem started.
Mazda CX-9 complaints by model year
Best CX-9 years: 2015, 2022, 2020. Years to avoid: 2012, 2011, 2018, 2008, 2010. Compare all years →
2021 Mazda CX-9 recalls (1)
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.
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.
What 2021 Mazda CX-9 owners say
Engine & cooling all 21 →
The contact owns a 2021 Mazda CX-9. The contact stated that while accelerating quickly and entering the highway, there was no motive power to the vehicle. While crossing the highway in the right lane, driving at 65 MPH, the vehicle in front moved over; there was a parked vehicle. The contact was able to stop the vehicle before causing a crash. The driver was starting to accelerate, but there was no motive power when the accelerator pedal was depressed. The smart brake system malfunction message was displayed. There were no warning lights illuminated. The contact called the local dealer, who scheduled an appointment. The vehicle was not diagnosed or repaired. The manufacturer was contacted and informed the contact to have the vehicle diagnosed. The failure mileage was approximately 53,186.
The contact owns a 2021 Mazda CX-9. The contact stated that while driving at 60 MPH or exceeding 60 MPH, the vehicle would lose motive power and stall without warning. The contact stated that he would coast to the side of the road and the vehicle would restart after 2-3 attempts and regain normal functionality. The vehicle had not been diagnosed or repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 49,000.
Driver assistance
I was in a parking lot and came to a stop and placed the car in reverse to back into a parking space. The back-up camera was on and I began to back into the parking space when the car suddenly lurched/jerked forward and accelerated on its own. The car jumped the parking lot median strip and I hit a tree head on. I had my seatbelt on and the airbag deployed. The car then reversed back off the median into the parking lot. I turned off the car. Insurance company will have it inspected. The vehicle is a total loss. I was injured with a large lower abdomen hematoma and airbag burns on arms, wrists, and chest as well as various bruising. I was fortunate to have not hit pedestrians who were walking in the lot or other vehicles that were parked in the lot. There were no warning lights, messages, sounds. The brake assist did not engage. It was frightening.
On 4/30/2022 the rear door lift gate opened unexpectedly and hit the ceiling of a parking garage (The Summit at Las Calinas, Irving Texas) , the glass window shattered, glass fell in and outside the car. An unfamiliar beeping was heard before the accident, but the source could not be located prior to the impact with the ceiling. A lift gate ajar warning indicator light likely flashed on the dash but was not noticed. We surmised that the root cause was likely due to unintentional pressing of the rear lift gate key fob button (driver had put key fob in pants pocket). This unintentional and unexpected opening of the lift gate has happened on at least 4 prior occasions when the key fob lift gate button has been unintentional pressed. One time resulting in being hit in the head with the lift gate! …
Transmission & drivetrain
I was in a parking lot and came to a stop and placed the car in reverse to back into a parking space. The back-up camera was on and I began to back into the parking space when the car suddenly lurched/jerked forward and accelerated on its own. The car jumped the parking lot median strip and I hit a tree head on. I had my seatbelt on and the airbag deployed. The car then reversed back off the median into the parking lot. I turned off the car. Insurance company will have it inspected. The vehicle is a total loss. I was injured with a large lower abdomen hematoma and airbag burns on arms, wrists, and chest as well as various bruising. I was fortunate to have not hit pedestrians who were walking in the lot or other vehicles that were parked in the lot. There were no warning lights, messages, sounds. The brake assist did not engage. It was frightening.
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.
2021 Mazda CX-9 engines & fuel economy
| Engine | Transmission | Drive | MPG city / hwy / combined |
|---|---|---|---|
| 2.5L 4-cyl turbo | 6-speed automatic | FWD | 22 / 28 / 24 |
| 2.5L 4-cyl turbo | 6-speed automatic | 4WD | 20 / 26 / 23 |
EPA ratings. Class: Small SUV.
Frequently asked questions
Is the 2021 Mazda CX-9 a good car?
Based on 40 owner complaints filed with NHTSA, the 2021 CX-9 rates average: 1.2× as many complaints as a typical year of the CX-9 at the same age. Complaint counts don't account for sales volume or individual maintenance, so have any used car inspected before buying.
What is the most common problem with the 2021 Mazda CX-9?
The engine & cooling — 21 complaints, 53% of all complaints for this model year. Next are the driver assistance (6) and transmission & drivetrain (5).
How many recalls does the 2021 Mazda CX-9 have?
There is 1 recall for the 2021 Mazda CX-9, the most recent from September 27, 2021 (mid/rear assembly). Recall repairs are free at any authorized dealer — check whether yours has been done with the VIN recall check.
What are the best and worst years of the Mazda CX-9?
The best years by complaints, compared at the same age, are 2015, 2022 and 2020. Years to avoid or approach with caution: 2012, 2011, 2018, 2008 and 2010. See the full Mazda CX-9 years comparison.
At what mileage do 2021 Mazda CX-9 problems happen?
The median mileage reported in complaints is about 53,000 miles; 50% of problems with a recorded mileage started before 50,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.