Adaptive Cruise Control problems of the 2019 Mazda CX-5

I purchased a 2019 Mazda Cx-5 (as is) on July 20, 2015. On September 11, 2025, as I was traveling on a three lane highway. I attempted to pass another vehicle. As I was attempting to go around the vehicle, my Mazda suddenly began braking and quickly losing acceleration. The speed limit on the highway was 70 mph. I estimated my speed at the time was between 70 and 75 mph as I attempted to pass. Pressing on the accelerator pedal did nothing. I had to try and very carefully steer the car to the right hand side of the road while trying to avoid oncoming traffic approaching from behind. When I finally got the car off the road, this is when I noticed that the car had stalled. The car started right back up and I continued to my appointment. The "radar cruise control" was activated at the time of the incident. On September 15, 2025, I contacted the dealer where the car was purchased and explained what happened. I was asked to bring the car in that same day. The car was supposedly looked over and connected to the service dept. 's computer to see if any error sign appeared. Nothing showed up. I service technician was then asked to ride with me to see if the car would replicated the same stalling as it has previously done. We could not get the car to stall as it had previously done. Before leaving, a salesman asked me if I wanted him to explain the "radar cruise control" to me some more. I agreed. The salesman then proceeded to tell me that "the car did not stall, it was simply braking from the activation of the radar cruise control". Being an experienced driver, I told the salesman that the car had stalled as evidenced by the fact that I had to restart it. The situation was not resolved to my satisfaction, but no other offers were made by the dealer. I requested additional diagnostic work to be done, but the dealer refused to cooperate. I did take the car to another Mazda dealer, but could get no offer but to connect the car to their computer.

When accelerating, the transmission feels jerky/stutters. The check engine light and traction control light are illuminated and on the instrument cluster the messages: "forward Smart city brake support malfunction", "Smart brake system malfunction" and "front radar sensor system malfunction" appear. The vehicle acts like it doesn't know which gear it should be in, it'll buck pretty hard and then it refuses to accelerate. . . It feels like it's in a "limp mode". A previous driver of the vehicle complained and said that it actually stalled in traffic on the highway and was of course difficult to steer due to loss of power. I took it to a dealership and they came up with a laundry list of things to fix. . . Most of which wouldn't have any bearing on this issue. I did have the serpentine belt replaced and the belt tensioner replaced due to wear on the belt and loose tension. On 7/16/25, I scanned the vehicle with a code reader, the codes p0301 and p0506 appeared. P0301 is a generic "cylinder 1 misfire detected" message and p0506 is a generic "iac system rpm lower than expected. The vehicle was taken to a shop where the spark plugs and the cylinder 1 coil was replaces and the iac cleaned. On 7/24/25 the same vehicle behaviors were observed and the same warning lights and messages were activated. I scanned the vehicle and got "p0300 random/multiple cylinder misfire detected and p0304 cylinder 4 misfire detected. There was a recall on this particular vehicle make, model and year and my vehicle was out of the VIN# range. I firmly believe that the recall needs to be expanded to include a larger number of vehicles. . . You can google about this vehicle and see many others with similar issues. Usually, the cure is a pcm reflashing/software update that seems to take care of the issue. Please expand the recall before someone dies in an accident because of this problem.