Mazda CX-9 sudden acceleration problems

Filed Aug 1, 2025 · Acceleration, Airbags · 173,000 miles · NY · crash

The contact owns a 2011 Mazda CX-9. The contact stated that while attempting to park the vehicle at a slow speed in the driveway, the vehicle suddenly experienced unintended acceleration, lurched forward, and crashed into a tree before coming to a stop. The contact was unable to stop the vehicle during the sudden unintended acceleration. During the failure the vehicle sustained front end damages, but no air bags had deployed. No injuries were reported. The cause of the failure was not yet determined. The contact stated that twice in the day before the unintended acceleration, the vehicle jerked forward in traffic however, the contact attributed the issue to the brake pedal not being firmly depressed or the clutch not properly engaged while shifting gear. The local dealer was notified of the failure, but no assistance was offered. The manufacturer was not yet contacted. The failure mileage was 173,000.

Filed Oct 16, 2023 · Driver assistance, Transmission · FL · 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, 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.

Filed Apr 25, 2021 · Brakes, Engine · 10,300 miles · NY

Happened to me two times in past three weeks, where I am coming to a stop, or hardly moving, and car suddenly accelerates. Had my foot on the brake and the car was still trying to accelerate. Yesterday, 4/24/21 it took all my strength on the brake to keep the car from pulling into oncoming traffic. I have been driving for 39 years and have owned many cars, and something like this never happened to me. I will be bring the car dealership tomorrow, the car has only 10k miles on it as we don't do a lot of driving with it as we owe two cars. I did not have my foot on the wrong pedal, this is very dangerous and if the dealer does not find anything with the car, I intend to sell it, as this is probably one of the scariest experience I had with a car. It is intermittent, so I am not sure when its going to occur, but twice in the last few weeks is not coincidence ( it also happened to my wife a few months ago, but we thought it could have been due to snowy road conditions). In one case I was coming up to a stop sign, and was braking and car was accelerating as I tried to break. I had to put car in neutral and the shut off car to get to stop. Yesterday, I was pulling out of a parking lot, and was waiting for an on coming car to pass me before I could turn onto road, when car was trying to accelerate, when I had my foot on brake, and took everything to keep the car from accelerating forward into on coming car. Once car passed, I made turn onto road, and issue did not repeat on the remaining mile to my house. I went onto a mazda forum and I saw a few others who raised the same concern/issue.

Filed Feb 22, 2021 · Acceleration · 112,000 miles · NY · crash

Tl* the contact owns a 2012 mazda cx-9. The contact stated that while driving approximately 5 MPH while pulling into a parking space, the vehicle suddenly experienced unintended acceleration and drove forward crashing into a wooden seating bench which was pushed into a building. During the incident the drivers foot was pressing the brake pedal. No injuries were reported. A police report was taken at the scene and the vehicle was towed away. The cause of the failure was not yet determined. The manufacturer and local dealer was not notified. The failure mileage was 112,000. The VIN was not available.

Filed May 10, 2019 · Acceleration · 56,000 miles · VA · crash

I was turning right into a parking space with my foot on the brake, when the car suddenly accelerated. The engine revved up and the car darted forward. For a split second I lifted my foot to make sure I was not pressing on the accelerator, and immediately pushed back down on the brake as hard as I could; the car continued to speed forward. Instinctively I kept the wheel turned to the right to avoid crashing into the building in front of me as the car jumped the curb, but I hit 2 parked cars. Once I was almost stopped by hitting the 2 parked cars, I quickly turned the key off and put the car in park. I have never experienced this issue before; and let me tell you, I was terrified. I have pictures that show tire marks either from the cars acceleration or dragging the back wheels from pushing on the brake.

Filed Dec 29, 2017 · Electrical, Engine · 24,000 miles · CA · crash

Immediately upon making a sharp right turn into a parking spot, the car suddenly accelerated at a very fast pace without me pushing the gas pedal. My immediate reaction was to press on the brake, but it did not stop. The car slammed into a planter in front of me. The car moved so quickly that it was lodged into the bushes and had to be pulled out by a tow truck. I immediately called the dealer service department and told them what happened. The service manager's immediate reaction was to scoff at the idea that the car accelerated on it's own. My husband met me at the dealer and had subsequently found information about a recall of cx-9 models from 2012 for a similar malfunction. He showed it to the same manager who immediately knew the issue of the recall but was quick to mention it was the 2012 model, not the 2016. The dealer kept the car for a few days and told me it was driven twice and also some info from the computer was reviewed with mazda tech support person. No data indicating any kind of malfunction in the car and the service guy did not have a problem with it in two short test drives, so they said come pick it up it's safe to drive. However, I will never drive this car again. This is the fully-loaded signature cx-9 that they feature in all their ads. I loved this car at first sight and drove it over 24000 miles in less than 2 years. This experience scared me to the point that I will never drive this or another mazda again. I have had over a week to process this experience and am just happy my kids weren't in the car or that I didn't hit someone. I have found several other instances of sudden unintended acceleration online and cannot believe that this happens in 2017. I hope that this documentation helps someone else in my shoes feel that they are not crazy and this does happen. Shame on mazda for not fully addressing this issue.

Filed Sep 23, 2017 · Brakes · 77,000 miles · WA

Hissing sound when braking in motion or parked. When driving up to an intersection after exiting the freeway about 20 MPH car would not stop no matter how hard I stepped on the peddle. Luckily I was able to slow before hitting the car in front of me. When stopped at a light car lunged forward while my foot was on the brake. This happened again while I was waiting for my daughter at school. It lunged up and nearly hit the car in front of me! Scariest thing in the world to not be able to brake!!

Filed Jan 21, 2016 · Acceleration · 41,010 miles · TX

Unintended acceleration in parking lot. Car was in drive, foot lightly on brake waiting on car in front to vacate parking spot. Engine suddenly surged and transmission made strange sound. Barely avoided running over an elderly pedestrian. This is about 4-5 time the car has done this in the last 6 months usually while waiting in a line of cars with foot on brake.

Filed May 12, 2015 · 35,982 miles · MN

I experienced unexplained sudden acceleration while stopped at a stop light. At the time of the incident there was one car stopped in front of me and one behind me. From the onset of the incident it took just a very few seconds, probably between two and four, for the engine to rev to an extremely high speed. While this was happenings I could feel the vehicle attempting to move forward forcefully while I was applying the brakes very hard. I shifted into neutral and turned off the ignition. I then shifted into park. I turned the ignition on again and the engine continued to rev at a very high speed. I immediately shut off the engine. I decided to start the vehicle one more time. This time when I turned on the ignition the vehicle ran normally. I cautiously drove it for possibly five miles and parked it where I could have it towed to the dealership. I was asked about floor mats.the original floor mats were in the very back of the vehicle and I had weathertech mats, in the front of the car, which were attached to hooks in the floor holding then in place. The dealership did take the situation very seriously. They did indicated concern about having the vehicle on the road again. They tested the vehicle for any computer codes which might indicate what may have caused the problem and found nothing. They contacted mazda and at the time that I sold the car back to the dealership they had not heard anything from mazda.

Filed Feb 11, 2015 · Fuel system · MD

Foul sulfur smell in cabin, gas smell odor, smelling gas fumes pungent fresh gasoline smell inside the cabin while driving. On the highways, or local roads. It last few minutes when opening the hood rotten eggs smells, the intensity varies, it happen sporadically, I used with different kind of gasoline, also different grade from 93-87. It would be ok for the first 100 miles then the same thing all over again .more noticeable with heat on high in the morning .it is almost the fuel injection railing are leaking ,or bad catalytic converter or it could be coming from the transfer case or bad heater core. I took it to the dealership few times , once I was told since it is new ,you need time to age the converter, finally it became unbearable , I took last monday , I was given a tsp issued by mazda to recommend changing gas brand every 100 miles which I have been doing , avoid sudden acceleration, which I am aware of , also the recommend avoiding short trips , I guess we are suppose to walk or have a bike inside the mazda to use on short drive. . It seems like it is on going problems with mazda since 2003. And they are insulting the public intelligence with their recommendation where they should come up with remedy to this toxic problem .. I hope your agency investigate this problem and hopefully made mazda do something about it .