2020 Mazda CX-9

Some vehicles may have coolant leaks at the cylinder head around the exhaust manifold. There may be cracks at the stud bolt hole or at the outside of the exhaust manifold - from Mazda's TSB. Excessive coolant leak leading to engine-overheating and going into 'limp mode' couldn't drive faster than around 30 mph. Mazda has repeatedly declined help with goodwill requests and any further assistance. ref. https: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

We were on the freeway and all of a sudden it stopped accelerating and the engine light, sensor light, and sensor warning came on. We could not accelerate, that became disabled and we had to pull over. My husband said our fluid levels were normal and he checked them all in the shoulder of the freeway. We turned the vehicle off then on again and all lights went away and we continued on. This is a safety hazard because the car would not accelerate while we were going 60 mph on the freeway. I quickly took a picture of the dash as this was happening so I can take it to the dealer.

While driving at freeway speed in Oregon, with 85 degrees ambient temperature and A/C inside set to 74 degrees, our CX-9 sunroof exploded outward. The sound was close to a very loud pop, and not the sound of rock/debris impact. At the time of explosion, there were no vehicles nearby and no overpasses from which an object could have dropped. The vehicle had been washed the day before and there was no visible damage to the sunroof. At the time of explosion, the sunroof and interior cover were closed. Upon stopping the vehicle (within less than one mile) inspection showed that nearly no glass fell downward, and approximately 50% of the total sunroof area had blown upward and out of the vehicle. The remainder of the shattered glass was still contained within the frame, with the edges visibly curved upward as though the glass had been pulled away from the car. There were three people in the vehicle at the time (driver, front seat passenger, and middle row passenger behind the driver). The two passengers were asleep and woke abruptly thinking we had been hit by something, as the explosive bang was followed by the sound of air rushing past the hole. There was no sound of glass rattling in the area over the sunroof cover, which seems to indicate glass had not broken inward and then blew out before stopping. I (driver) kept the cover closed and promptly pulled off the freeway to assess damage. I was unable to visit a dealer for warranty assessment due to vacation travel. A phone call to my local dealer did indicate it should be covered under warranty but it has not been inspected, this has not yet been confirmed. I rarely open the sunroof cover and have only opened the sunroof itself 3-4 times since purchase two years prior (2020). I did open the sunroof to give my son fresh air on curvy roads approximately one hour prior. No injuries, but if the cover had been opened we may have had glass falling into the cabin. No other visible or audible warnings occurred.

On 10/12/2021 we were driving on and urban street when the vehicle infront of us signaled and initiated a right hand turn. At that point were we traveling approximately 20 mph, and we were driving with active cruise disengaged. When we were around 150 feet behind the vehicle taking a right when our CX-9 falsely engaged the emergency braking. Our car with our whole family in it locked up the brakes and stopped in 80 feet short of the car taking a right. The vehicle behind us only managed to stop 10 feet short of hitting us in the rear. It is in the 4 people in our vehicles opinion that this operation was both terrifying and dangerous to use and those following.

The 2020 Mazda completely shut off following an exit from an expressway, turn under a bridge and slow down for a red light. The Mazda electrically shut off and coasted to a braked stop in the center lane of a 3 lane road. The entire electrical system went dead, no exterior lights, signals, instrument panel or radio. There was no warning, everything electrical just shut off. In a moving traffic situation the car could not maneuver or restart without being placed in PARK. (There is a history of Mazda CX 9's having a similar problem which sent the driver to the local dealership.) The car was restarted by shifting into Park and pressing the start button, all functions appeared normal as the driver moved it to a parking lot to review the situation. The driver was unable to re-create the complete shut down and finished the trip. The driver took the Mazda to the dealer following the incident and was asked to leave the Mazda for observation. The driver was notified by the dealership that the problem was being elevated to the national team for diagnosis. 10 days later the local dealer called the driver and said that they; nor the Mazda engineers in California; could reproduce the system shutting off or find any error codes. They wanted to return the car to the driver with no need for a repair. The driver spoke to the National Mazda help line and the representative was aware of the situation. The representative reiterated that engineers had been unable to find the source for the incident in the computer logs so they could not provide a remedy. The representative offered the driver the choose of a purchase buy back and a discount on the purchase of a new car.

FUEL CAP LIGHT ON IN DEC 2020. OUR CAR MILEAGE ~14,000 MILES . WE BOUGHT BRAND NEW CX9 2020 IN AUGUST. DEALER INSPECTED IT AND FOUND NOTHING WRONG. DEALER REPROGRAMMED IT. A MONTH LATER JAN 1,2021, FUEL CAP LIGHT IS ON ON AGAIN. WE IGNORED IT THINKING IT IS ANOTHER PROGRAM ISSUE. CAR STARTED TO JERK AND VIBRATE AT STOP SIGN. WE BROUGHT TO DEALER THE NEXT DAY. DEALER SAID CHARCOAL BOX IS LEAKING. I THOUGHT CHARCOAL BOX SHOULD LAST A LIFE TIME. THEY SAID IT IS NOT UNDER WARRANTY: $680 LATER, THE JERKING/VIBRATING ISSUE IS FIXED. HOPEFULLY THAT IS IT SINCE WE ONLY HAVE THE CAR FOR 5 MONTHS

THE MAZDA CX-9 UNCOMMANDED ENGINE ACCELERATION REPORTED HEREIN DID NOT RESULT IN ANY DAMAGE PRIMARILY BECAUSE IT COMMENCED SEVERAL SECONDS AFTER I BEGAN LIGHT BRAKING WHILE APPROACHING A RED TRAFFIC LIGHT. MY IMMEDIATE RESPONSE WAS TO INCREASE BRAKE PRESSURE; THERE WAS NO NEED FOR ME TO MOVE MY LEG OTHER THAN PRESSING HARDER WITH MY FOOT. MY FOOT HAD BEEN OFF THE ACCELERATOR FOR MANY SECONDS WHILE ALLOWING THE CAR TO SLOWLY DECELERATE WHILE COASTING TOWARD TRAFFIC STOPPED AT A RED LIGHT. WITHIN TWO SECONDS OF COMMENCEMENT OF UNCOMMANDED ENGINE ACCELERATION AND WITH THE CAR FULLY STOPPED, I SHIFTED THE TRANSMISSION INTO NEUTRAL. THE ENGINE IMMEDIATELY GENERATED THE NOISE OF VERY HIGH RPM. ALTHOUGH THE DASHBOARD INCLUDES A TACHOMETER, I DID NOT IMMEDIATELY THINK TO LOOK AT IT; INSTEAD, I TURNED THE IGNITION OFF. A FEW SECONDS LATER, I SHIFTED THE TRANSMISSION INTO PARK AND RESTARTED THE CAR WHICH OPERATED NORMALLY THEREAFTER. MY FOOT DID NOT MOVE OFF THE BRAKE PEDAL DURING ANY OF THE PRECEDING SEQUENCE. ONLY THE NHTSA AND POSSIBLY THE MANUFACTURER WOULD KNOW IF THIS IS A ONE IN A BILLION-HOURS OR A MORE COMMON OCCURRENCE. I AM WILLING TO ANSWER ANY QUESTIONS THE NHTSA OR THE MANUFACTURER MIGHT HAVE. I GRADUATED FROM MIT, WORKED OVER 29 YEARS FOR THE LEADING USA COMMERCIAL AIRCRAFT MANUFACTURER AND AM CURRENTLY RETIRED.