2023 Mazda CX-9 problems

“I am reporting a critical mechanical restraint failure regarding the 5-point harness crotch buckles on the Graco TrioGrow and the Graco TriRide car seats. The red button-release tension on both of these models is engineered with insufficient physical resistance. My toddler is capable of physically depressing the lower crotch buckle and completely freeing themselves while the vehicle is traveling at highway speeds. The harness was explicitly verified as tight via the pinch test and the chest clip was at armpit level, proving the failure is strictly the low force required to disengage the buckle.I contacted the manufacturer (Graco), and their customer support agents dismissed this hardware failure by suggesting 'behavior modification' instead of addressing the mechanical vulnerability. A child restraint system must physically restrain the occupant regardless of behavioral variance. This is an active, ongoing safety hazard for young children traveling in these specific models”

“On February 9, 2026, our 2023 Mazda CX‑9 experienced a sudden and complete system malfunction while being driven. Multiple system failures began approximately six minutes before the crash. During this time, the driver reported: • Total loss of steering • Complete brake failure • No response to acceleration or driver input • No ability to slow, stop, or maneuver the vehicle • No meaningful warnings that allowed corrective action The vehicle became completely uncontrollable. At the crash site, there were no skid marks, no braking evidence, and no signs of evasive action, consistent with a full loss of vehicle control. The vehicle only stopped after entering approximately two feet of water and striking a tree. The vehicle was declared a total loss. This incident represents a severe safety defect involving critical electronic and mechanical systems. A modern vehicle should not lose all steering, braking, and control functions under any circumstances. We are requesting a full investigation into the cause of this failure and whether similar incidents have occurred in other Mazda vehicles. We can provide photos, crash documentation, diagnostic information, and driver…”

“If you press both the brake and gas at the same time (even if accidental), the onboard computer apparently thinks that the driver is confused, and it sets the gas flow to “idle”. The first time this happened was on the freeway, and I was very lucky to be able to coast into a gas station (thinking that I simply running out of gas - even though the gas gauge showed plenty of gas remaining). And so, I took it to Christian Brothers automotive the next day, and they ran extensive (and expensive) diagnostics. They found (to their surprise!) that this is the way the latest CX-9 works! The computer sees that you are on the gas and brakes, and so it “thinks” that you must be confused. And so, it sets the gas to “idle”. I believe this is an extremely dangerous action for the computer to take, and this behavior needs to be removed from all CX-9's IMMEDIATELY! And please don't just say (as others have) that the driver "shouldn't press both the brake and accelerator at the same". One might use the brake and accelerator at the same time for good reason, such as an icy road. But the computer SHOULD NOT DECIDE ON ITS' OWN TO SET THE THROTTLE TO IDLE!”

“Starting [XXX], through [XXX], we began receiving multiple "Critical Vehicle Malfunction" alerts (46 alert messages)via the Mazda app, including "Parking Brake Malfunction" and "Electric Parking Brake Malfunction." During this time, the vehicle experienced delayed starts and eventually required a jump-start. We brought it to the dealership multiple times to show the messages, before our 3-year/36,000-mile B2B warranty expired, but the issues were dismissed until the battery was finally replaced. At just over 36,000 miles (currently 39,646), a new issue emerged a “thud” sound from the steering wheel. The dealer diagnosed it as a failed u-joint shaft, which was deemed non-serviceable and not covered under warranty. I inquired about potential causes or prevention—no clear answer was known. I found relevant NHTSA TSBs (06-001/20 & 06-001/24) related to steering issues and escalated to Mazda USA. Mazda agreed to cover 50% as a goodwill gesture, leaving me to pay about $500. Two weeks later, the part arrived and was installed—but it did not fix the issue. The dealership now says it’s a failed bearing within the Electric Power Steering (EPS) unit, which requires…”

“Structural bolt (p#: 9-YA01-1401-A) connecting the lower control arm assembly to subframe has rusted apart. The head of the bolt was found in my driveway, otherwise there would be no indication of this potentially catastrophic failure. Vehicle is only 3 years old, was a cpo purchase, and has just 55k miles. Underbody is clean of rust. This is 100% a defect. This is a safety issue. Old bolt will need to be extracted and replaced. Not confident in other bolts so will need to at least inspect those. Hopefully, I can update this will the repair estimate from manufacturer.”

“I recently purchased a 2023 Mazda CX9 with factory installed tires, Falken Ziex CT50 A/S p255/50R20 104V M+S. I was driving on the freeway on Tuesday [XXX] going around 65-70MPH. My tire pressure light came on all of a sudden, I started to slow down and make my way over to the right lane and then shoulder to check it out and all of a sudden the tire tread completely ripped away from the rest of the tire. Some of the sidewalls stayed intact, which ultimately protected my wheel from damage. But other than the tire pressure light coming on 30 seconds before the failure, there was no warning, no obvious defect or anything in the tire. Had it been one of my front tires it potentially could have been way worse of an outcome as I was driving on a bridge and next to a semi. The shop where I ended up replacing all 4 tires because I did not feel safe using this brand any longer said he has never seen the tread just rip right off of the sidewalls. I searched the tire make and model and there was an open recall on this specific brand and size tire, but my date stamp did not match. However, it was the same exact reason for the recall in the first place. So clearly this…”