2021 Mazda CX-5

I was sitting at a traffic light with my foot on the brake waiting to turn left onto Lee Highway from Fairfax County Parkway. Car jerked forward TWO times in a row, both times hitting the car in front of me. Our lane was at a dead stop waiting for the left hand arrow. The cars to the right of us had the green and were moving forward. I felt like I had no control over the car during this time.

The vehicle's Connectivity Master Unit (CMU) suffers from a severe, persistent electronic hardware malfunction that causes the central information display and dashboard telemetry to blink, cycle, and drop signals erratically. This specific hardware architecture failure threatens to corrupt data transmission lines directly connected to the Advanced Driver Assistance System (ADAS), creating an imminent safety risk of unintended automatic emergency braking or false sensor deployment during highway transit. The vehicle utilizes the exact same defective CMU hardware component that the manufacturer has acknowledged and recalled on other model cohorts; however, the manufacturer has explicitly excluded this specific VIN from safety recall eligibility. Diagnostic attempts by the authorized dealer network relied solely on forcing digital software updates that completely failed to correct the core hardware signaling instability, leaving the vehicle un-repaired and presenting an active, unmitigated electrical and safety hazard on public roads.

2021 Mazda CX5 AWD- Non Turbo Engine. Sunny Day, Dry. My Car was clean. No Precipitation. Some shadows of the interstate light poles across the road 200-300 feet in front of me, but they were thin shadows. Sun Was to my Left. I was driving South on May 01 2026 about 10am on the Interstate going Highway Speeds, with adaptive cruise control "on", in the 2nd lane of a 4 lane interstate. Thankfully no other traffic ahead or behind me. Car slammed on the brakes suddenly, pretty hard. I counteracted and added more gas pedal to keep in going. I turned off the Cruise Control. After a while I re-engaged the Cruise Control and had no issues. This could have been a huge accident in busier traffic. Will get the car checked out at Mazda Dealership Service this week.

The contact owns a 2021 Mazda CX-5. The contact stated that while driving at an undisclosed speed, the Forward Collision Avoidance Automatic Emergency Brakes activated unintendedly, and the vehicle jerked to the left and independently accelerated and moved back in the lane intended lane. The vehicle then jerked to the right, unintendedly accelerated, and then went back into the intended lane. Then the vehicle resumed normal operation. While driving approximately 60-65 MPH a week later, the vehicle started jerking. The “Smart City Brake Malfunction” message was displayed, and the engine warning light was illuminated. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 114,000.

2021 Mazda CX-5. On 8/6/24, I turned right into a parking space between 2 parked vehicles at the DMV parking lot. I turned right and eased into the parking space facing a large Ford F 150 white pickup truck. I was approximately 1-1.5 feet from the front of the white truck. I had my foot on the brake, suddenly the vehicle accelerated by itself and I heard the car revving at a very high rpm and the car took off. My sister was a passenger and she heard it as well. None of the collision or brake notification avoidance features came on the screen or were implemented as a safety measure or accident prevention. I had my foot on the brake and I had no control over the vehicle. The car lurched forward hitting the right side near the headlight of the car on my left and the pickup that was in front of me. My car hit the white pickup so hard that it pushed it out of the parking space in front of me and perpendicular to the parked cars in the row. We both were injured, my sister in ICU and had to have emergency cervical surgery for fractures impinging her cervical spinal cord. The Mazda was totaled. It is impossible for a Mazda to push the Ford F 150 pickup truck, that was facing me , out of the parking space and perpendicular to the row of parked cars with just 12- 14 inches between the pickup truck and my vehicle unless it was revved up to a very high rpm. The police report has some inaccuracies, it states I was turning left into the space but was actually turning right and says I possibly passed out but that is not true. I was in shock when the police questioned me. I have also relived every second of this accident in slow motion many times since. I am a 5 foot women and would have had to floor the gas peddle and even then would not be able to push a large pickup truck out of the space in front of me, and continue out of the parking space landing sideways in a 12-14 inch space between the front of the 2 vehicles.

Will driving on the interstate, using the adaptive cruise control feature, vehicles were slowing down to a stop ahead and my car accelerated instead of slowing down. I then pressed the brake and simultaneously, the car breaks locked down (automatic braking). Unfortunately I wasn’t able to avoid an accident as I rear ended the vehicle in front of me. My vehicle has been turned over to the insurance company to assess damage. I’m sure it can be inspected by nhtsa. Mine and others safety were at risk due to the malfunction of the cruise control accelerating instead of stopping. It caused an accident. Luckily no one was extremely injured. I have neck and back pain from the collision that will hopefully heal in a few days. Time will tell. But this could have been much worse had I not reacted as quickly as I did. This could cause a fatal accident. The care isn’t drivable so it has not been reproduced by anyone. I have notified the insurance company about the issue and It is my hope that they will inspect this. There were no warning lights or messages displayed prior to the incident.

I experienced a sudden unintended acceleration incident. I pulled into my driveway and stopped the vehicle with my foot firmly on the brake since my driveway is sloped. I pushed the garage door opener remote when suddenly the vehicle accelerated and shot forward hitting the garage door. There was no brake action and all backup systems failed. There was no Automatic Emergency Braking or Forward Collision Warning. There were no warning lights displayed. No airbags were deployed. If the garage door had been open, the vehicle would have hit a concrete wall in the garage. The vehicle was taken to the Mazda dealership and a full circle inspection and diagnostic check. Mazda found no codes and everything was working as designed in vehicle.

Feb 2,2022 received Critical Vehicle Malfunction Warning, all vehicle systems affected told to call roadside assistance and not to drive vehicle. Received same warning again February 11,2022 after vehicle had been inspected by dealer service again had vehicle towed to dealer. April 14, 2022 Critical vehicle malfunction again. October 30, 2022, again Critical vehicle malfunction warning. All vehicle systems affected.