2019 Mazda CX-5: adaptive cruise control problems

Filed Feb 27, 2026 · Acceleration, Driver assistance · PA

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.

Filed Jan 4, 2023 · Driver assistance · OH

My 2019 Mazda CX-5 automatically applied the brakes while the car was on cruise control traveling at 65 mph on a highway, and there wasn't a car or any object in front of me or to either side of my car. The car applied the brakes firmly and brought the speed down quickly and dangerously. I quickly depressed the accelerator to get the car back to highway speed to avoid a rear-end collision. This issue has happened 3 times in the past 2 weeks, all while traveling at highway speeds on cruise control for an extended period of time (hours). I believe this is the same issue with the Mazda Smart City Brake Support system that led to a recall of 2019-2020 Mazda-3 vehicles. My Mazda CX-5 is out of warranty and the dealer stated it is not covered by the recall.

Filed Feb 13, 2022 · Acceleration, Driver assistance · WA

On interstate 90 while driving at 75 mph under cruise control I passed an 18 wheel truck on a curve. With no cars in front and two following, the car without warning braked heavily and control screen flashed warning BRAKE. The car immediately behind braked and veered on the bearm to avoid me. I stepped on gas to override the brakes and avoid an accident.

Filed Jun 15, 2021 · Electrical, Engine · CA

Driving on highway, cruise control ser to 82, no cars in front. The car suddenly jolted twice, engine light and battery light comes, lost of power. Pulled over to shoulder in the middle of nowhere in Nevada. Tried to start the car, engine won't turn on, starter just kept cycling. Veh temp was just below 210 with a 1/4 tank of gas. Called dealership and service person asked is to use key to turn on car, no change and provided no other solution other than to take to dealership with the closest one being over 300 miles away. We decided to unhook and rebook the positive side of battery. Car restarted and currently driving it home as I write this complaint. 600 miles overdue for maintenance (by date due on July 26, 2021) and was scheduled upon return from trip which at the time should be approx 1000 miles over due.

Filed Feb 11, 2020 · Acceleration · 2,100 miles · WA

Mrcc (mazda radar cruise control) will unexpectedly decrease vehicle speed when in a turn even if not following another vehicle. Speed decrease happens regardless of vehicle speed. Amount of decrease is severe depending on "sharpness" of the turn, but will happen even on gentle sweeping turns on an interstate highway. Behavior is reproducible during all variety of driving conditions.

Filed Nov 9, 2019 · 2,995 miles · NY

While driving on the highway with very light snow falling and less than an inch of wet on the road, the "front radar blocked" message appeared! Upon later research into the mazda owner's manual it indicates the following systems were not functioning: mazda radar cruise control (mrcc) mazda radar cruise control with stop & go function (mrcc with stop & go function) distance recognition support system (drss) smart brake support (sbs) apparently the location of the front radar is behind the emblem in the center of the grill. Mazda recommends that the owner clean off the emblem of any dirt or snow to correct this problem. Driving on the highway it is not practical to pull over and clean off the emblem when it will happen again in these conditions. This is a serious design flaw that can lead to accidents. The front radar should be relocated in a location not subject to road splatter. It could be located with the other sensors behind the mirror in the middle top of the windshield.