2021 Mazda CX-9 Problems & Owner Complaints

Engine 19

“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 cylinders 2 & 3. Autozone detected codes P0300 with Secondary DTCs U0442-00 4) There car was only inspected by the…”
NHTSA complaint #11752508, 2026

“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 interval. The dealer did not detect oil leaks in any of the engine systems. 2. I presented the vehicle to the dealer with…”
NHTSA complaint #11749820, 2026

“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 of the recall range and has 87k miles on it. Other research online shows other people with the same vehicle and similar…”
NHTSA complaint #11745150, 2026

Unknown Or Other 6 2 crash 1 injury

“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, w…”
NHTSA complaint #11550295, 2023 · crash · 1 injury(ies)

“REAR PASSENGER HANDLE AND HOOK ABOVE SEAT IN ROOF SPLINTERED INTO SHARP PROJECTILES FLYING THROUGH CABIN WHEN AIR BAG DEPLOPYED I SHOWED THE SHARP PIECES TO MY INSURANCE ADJUSTER THE POWER OF THE RIGHT CURTAIN AIR BAG DEPLOYMENT BROKE THE HANDLE TO PIECES AND IF ANYONE HAD BEEN IN THE BACK SEAT THEY COULD HAVE HAD AN EYE PUT OUT OR BEEN EMPLAILED BY THE SHARP PIECES”
NHTSA complaint #11489125, 2022 · crash

“My MazdaCx9 engine consumes (burns) an excessive amount of oil, necessitating frequent top-offs between oil changes.This issue started after the first oil change and continued since then.”
NHTSA complaint #11632117, 2024

Service Brakes 4 2 crash

“The driver side airbag did not deploy in a front end collision on the drivers side. When approaching a vehicle that had come to a sudden and complete stop, the brakes were applied hard to the Mazda CX-9 in order to stop, but after about 1 second they just totally let go and there was no braking at all and the Mazda continued to move forward until it slammed into the vehicle that was stopped. The MyMazda app sent a message that stated that there was a Brake System Malfunctiom which is exactly what occurred and caused the accident.”
NHTSA complaint #11495745, 2022 · crash

“AS I WAS DRIVING DOWNHILL WITH MINIMAL SNOW ON THE GROUND, I TAPPED MY BRAKES ABOUT 7 TIMES BEFORE THEY LOCKED UP. I WENT TO TURN TO STAY ON THE ROAD AND THE STEERING WHEEL WOULDN'T BUDGE CAUSING ME TO GO OFF THE ROAD, INTO AN EMBANKMENT. VEHICLE WAS GOING ABOUT 5-10MPH WHEN THIS OCCURED ON A CITY STREET.”
NHTSA complaint #11397703, 2021 · crash

“Hello, I have been to a Mazda dealer complaining of clicking and squeaky brakes for 2 years now. Dealer replaced both front and back breaks and rotors around 22k year ago and to my surprise the issues persist, currently vehicle is at 49k. There is a TSB( 04-001/22) out for my vin and year, so they know its a manufacturing defect and all they do is throw white break grease and a month later the noise is there again when breaking , backing up. I am not the only one, people of reddit confirm this and so does a general google search. Besides that i love the car and the dealer was super cool a…”
NHTSA complaint #11619774, 2024

Forward Collision Avoidance 3 1 crash 1 injury

“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, w…”
NHTSA complaint #11550295, 2023 · crash · 1 injury(ies)

“On [XXX], [XXX], [XXX] I was driving on an interstate highway with a 65 mph speed limit with no warning and received the following codes which slowed the vehicle to the limp mode. 1) Smart Brake Support and Forward Obstruction Warning 2) Activsense system malfunction 3) Front Radar Sensor Malfunction 4) Engine Malfunction 5) Dynamic Stability Control Malfunction I reported all three incidents to the dealer and no codes were left and the dealership had no solution for the problem. They suggested dirt, sunlight, or blowing debris caused it, but that was not the case. Luckily the first two i…”
NHTSA complaint #11627970, 2024

“6/29/2023--Vehicle stopped suddenly with i-ACTIVESENSE system malfunction, Dynamic Stability Control malfunction, Engine malfunction, engine output reduced, Front radar sensor malfunction. Dealer said these faults due to bad battery--replaced battery per Service Manager [XXX] at Lakeland Mazda. 9/10/2023--Incident #2 with same faults as above with vehicle stopping suddenly at risk of creating a rear end collision. Lakeland Service Manager [XXX] now said that the faults are due to a faulty ERG valve. Lakeland Mazda and [XXX] are absolutely clueless as to the root cause of this problem and a…”
NHTSA complaint #11548334, 2023

Air Bags 2 2 crash

“2021 Mazda CX-9 Frontal collision at a speed between 10-20 mph. Car shut down after collision and was not drivable. Concern is the driver side airbag did not deploy. (Neither did passenger but there was no person in the passenger seat)”
NHTSA complaint #11523765, 2023 · crash

“REAR PASSENGER HANDLE AND HOOK ABOVE SEAT IN ROOF SPLINTERED INTO SHARP PROJECTILES FLYING THROUGH CABIN WHEN AIR BAG DEPLOPYED I SHOWED THE SHARP PIECES TO MY INSURANCE ADJUSTER THE POWER OF THE RIGHT CURTAIN AIR BAG DEPLOYMENT BROKE THE HANDLE TO PIECES AND IF ANYONE HAD BEEN IN THE BACK SEAT THEY COULD HAVE HAD AN EYE PUT OUT OR BEEN EMPLAILED BY THE SHARP PIECES”
NHTSA complaint #11489125, 2022 · crash

Back Over Prevention 2 1 crash

“Backup camera shows three to four feet before red collision line is not accurate causing severe damage to my garage door.”
NHTSA complaint #11704278, 2025 · crash

“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 unexp…”
NHTSA complaint #11463223, 2022

Power Train 2 1 crash 1 injury

“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, w…”
NHTSA complaint #11550295, 2023 · crash · 1 injury(ies)

“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 in the powertrain relate to oil consumption. The cylinders are part of the powertrain and carbon buildup from excessive…”
NHTSA complaint #11665046, 2025

Electrical System 1

“The oil light keeps coming on before your initial oil change. Also, the oil is actually low. They have already changed it and I'm having the same problem in less than 2 months.”
NHTSA complaint #11537195, 2023

Steering 1 1 crash

“AS I WAS DRIVING DOWNHILL WITH MINIMAL SNOW ON THE GROUND, I TAPPED MY BRAKES ABOUT 7 TIMES BEFORE THEY LOCKED UP. I WENT TO TURN TO STAY ON THE ROAD AND THE STEERING WHEEL WOULDN'T BUDGE CAUSING ME TO GO OFF THE ROAD, INTO AN EMBANKMENT. VEHICLE WAS GOING ABOUT 5-10MPH WHEN THIS OCCURED ON A CITY STREET.”
NHTSA complaint #11397703, 2021 · crash

Suspension 1

“The contact owns a 2021 Mazda CX-9. The contact stated while driving at various speeds and turning, there was a popping sound coming from the front end of the vehicle. The front-end popping sound also occurred while driving over bumps in the roadway. The vehicle was taken to an independent mechanic who was unable to determine the cause of the failure. The vehicle was not repaired. The local dealer and manufacturer were not notified of the failure. The failure mileage was 68,811.”
NHTSA complaint #11617410, 2024

Vehicle Speed Control 1

“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 sc…”
NHTSA complaint #11608556, 2023

Visibility/Wiper 1

“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 unexp…”
NHTSA complaint #11463223, 2022

Wheels 1

“I was driving approximately 75-80 mph (speed limit for I-90 is 80 mph) on I-90 Eastbound in South Dakota (approximately 5-8 miles from Sioux Falls, SD) in the left-hand lane (passing lane with a minimal shoulder) when I heard a terrible noise that sounded like I had a flat tire and the car began to pull to the left. I immediately slowed down and steered the vehicle onto the small shoulder on the left-hand side of the interstate. It was at this point I looked out my window (driver's window) and saw the entire left front wheel (not just the rubber tire) rolling by (west in the grassy median of…”
NHTSA complaint #11542823, 2023