The engine coolant system/electronic coolant control valve is known for failing on the N/A Skyactiv-G engine. When it fails, it fails stuck open. There is a TSB out for this problem (01-011/21). This results in the engine coolant never making it to operating temperature, and poor heater performance during cold weather. When I took it to a dealer, they stated that the check engine light must come on from DTC P0126:00 before they can address the problem under warranty. Even after driving the car and having 30+ minute drives where the temperature gauge never makes it past the first tick (blue), I haven't had the check engine light come on. It's unclear what circumstances are required for DTC P0126:00 to occur, but I've never had a car essentially not get warm during an entire 30+ mile highway drive, even when it's 0 fahrenheit outside. It appears like this is a degenerative problem as I did not have this problem last cold season. This year, since the first day it has been colder than about 45 degrees, the engine has struggled to reach operating temperature, and of course is even worse now that it is colder. Without the heated seat, it would be difficult to be comfortable in this car due to this problem.

- Ann Arbor, MI, USA

Vehicle will over heat and then show warning messages that auto light system malfunction and engine will shut off randomly.

- Austin, TX, USA

Vehicle in motion at 65 mph. Very small rock chip breaks glass from left to right calling for complete replacement. Glass is highly fragile and too thin. Second occurrence in less than one year.

- The Woodlands, TX, USA

I driving uphill on a residential street. As I started to slow to turn the smart brake support flashed brake on my dash and immediately engaged the brakes and stopped the car. The road had a very slight curve with a few cars parked. There were no other moving vehicles in the area. If a car had been behind me it would have caused an accident. The system has given false warnings a lot but this was this first time that it stopped the car. I brought it to the dealership 2 days later and they tested the car and said it is working normally.

- Carlsbad, CA, USA

Radar cruise control malfunction and safety systems malfunction frequently. Safety systems completely disable without warning periodically while driving. Radar cruise control doesn't work randomly. Mazda dealership can't replicate the issue. Other 2019 Mazda 3 owners have the exact issue and no recall or fix has been issued.

- Little Rock, AR, USA

Fail sbs and sistem of detection of proximity

- Porter Ranch, CA, USA

Jan. 23, 2020. 10:45 am. I was on my street, a narrow residential street, preparing to back in my garage. In order to do that on this narrow street, I touched the lip of the driveway across the street. Speed well under 3 mph. When I did so, my car suddenly sharply accelerated and at the same time swerved to the right. The acceleration and swerve drove the car into the townhouses across the street from my house. The driveways are very short, barely a car's length. After crashing, I could feel the car still accelerating. I quickly switched the car into park and the spontaneous acceleration continued. In order to stop in I had to turn the car off. When the towing company turned the car on later it immediately started to spontaneously accelerate and surge forward again. The Mazda dealer and insurance inspector explained to me that there is a sensor: When a wheel encounters what it perceives to be an obstacle, it 'tosses' all the power to that wheel and accelerates. These driveways have a small lip at the edge. This sensor reacted to it in a way that caused my car to crash. The car was totaled and the townhouses across the street damaged. Thank heaven there was no one outside or they would have been killed. This needs to be investigated, recalled and changed.

- Kensington, MD, USA

Vehicle is 2 months old and the automatic emergency braking is going off in the middle of the street with no cars around. Today it went off in the middle of traffic and luckily the driver behind me was paying attention. I called the dealer to ask about servicing the recall and they said they did not have a solution. When I told them I almost got rear ended. Their response was thank goodness you didn't and if there was anything else they could help me with. Zero offers to help or concern for an obvious safety issue with this vehicle.

- Kissimmee, FL, USA

Car has given multiple warnings that driver and safety assist features are disabled -- despite not being enabled. Car also gave a camera malfunction warning approximately 1 minute before slamming on brakes unexpectedly at 35-40mph and causing injury to driver;incident occurred at clear night with no other cars around. Car currently in shop; no word on what caused this or when it will be repaired.

- Houston, TX, USA

While the vehicle is in motion the right side blind spot monitoring system does not work occasionally. Sometimes this happens with a warning message but sometimes it happens without a warning. Multiple repair attempts have been made but the issue still keeps happening. Mazda is trying to work on this issue but is not able to figure out what is wrong with their vehicles.

- Redwood City, CA, USA

My car's collision warning engaged without cause. It makes the car brakes abruptly for no reason. This is especially dangerous during highway speed. It happened 3 times so far in the 4 months that I own the car. Some other owners also experienced this.

- Jacksonville, FL, USA

The entire vehicle safety system malfunctions at random times while driving, most recently on the highway. The dashboard illuminates stating "safety and driver support systems partially disabled, drive safely". I lose blind spot monitoring, lane keep assistance, radar, and city brake support, among other things. This has happened several times over the past 2 weeks.

- Silver Spring, MD, USA

- rear view mirror fell off while on the freeway. Hot days will break down the adhesive and cause the rear view mirror to fall off. - brakes vibrate harshly when in sport mode. Faster the vehicle goes, the more harsh the brakes will vibrate. - acceleration is jerky on low end (1st/2nd) gear. In stop and go traffic, or going up-hill on load, acceleration will feel jerky when try to keep a steady speed between 5-15mph. Car feels normal when pushing the acceleration harder.

- Torrance, CA, USA