2021 Mazda CX-9 problems

“2021 Mazda CX-9 (VIN: JM3TCBDY3M0538768 / 72,400 mi) Vehicle has suffered complete, sudden loss of motive power at high freeway speeds on four separate occasions. Without warning, the engine loses all propulsion, essentially stalling mid-traffic and forcing me to dangerously coast across active freeway lanes to the shoulder. This creates an extreme risk of a high-speed rear-end collision. No crash or injuries have occurred yet, but the car is entirely unsafe to drive. The authorized Mazda dealership has been completely unable to diagnose or fix this intermittent failure. Due to the persistent danger, the vehicle is currently at the shop with the same problem, where it has been since Oct 8, 2026. This is not an isolated issue. As you will see from the pictures, there are several dates where the same situation has occurred in the vehicle goes into limp mode. Mazda corporate has been contacted case 00503976. I am requesting a buyback. I request an urgent NHTSA investigation into 2021 CX-9 power loss defects for a potential recall.”

“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 increasing. I could not accelerate at all. An exit was thankfully immediately available. I took the exit, then continued on a side road, then into a parking lot before I could find a safe place to stop. At no point did the pedal work again — I was immensely lucky to navigate safely, especially with my toddler in back seat. Other traffic was present on the interstate at the time. The sudden loss of throttle at that speed, with traffic present on each road and merging across numerous lanes in [XXX] traffic, created a serious risk of collision while I searched for a safe stop. The vehicle has not been inspected by a dealer, it’s with Hiley Mazda of Hurst dealership in [XXX] now. TBD whether the…”

“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 incidents happened with little or no traffic around but the third was during rush hour and almost caused a major accident trying to get off the highway. I shut the car off, restarted and the problem resolved no lights left on or warnings appearing all three times. Contacted Mazda several times and all representatives at the dealership and California Headquarters claim no knowledge of this happening. I found a few others reporting the same issue and wanted to report this.”

“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 about it all but I'm sorry, this is unacceptable, Every time i go get an oil change i ask about a fix and nothing.”

“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.”

“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.”