There are 5 owner-reported brakes complaints for the 2016 Mazda CX-9in NHTSA's database. These are unverified consumer reports and may not reflect confirmed defects.
Brake Booster damaged. I ended up with no brakes and nearly crashed.
MY WIFE AND DAUGHTERS TOOK A TRIP, AND ON THE WAY HOME, THE ENGINE LIGHT CAME ON. WHEN TURNING ON THE ENGINE TO CHECK THE ENGINE LIGHT, I NOTICED THAT THE BRAKE PEDAL WAS HARD. I WAS THINKING THE ENGINE LIGHT HAD TO DO WITH THE GAS CAP NOT BEING ON TIGHT SINCE FAMILY PURCHASED GAS ON THE TRIP BACK HOME. I DROVE THE CX-9 TO AUTOZONE TO DETERMINE THE CODE FOR THE ENGINE LIGHT. THE ATTENDANT AT AUTOZONE WAS UNABLE TO REGISTER A CODE. HOWEVER, I NOTICED THE BRAKES FELT DIFFERENT ON THE DRIVE TO AUTOZONE. ALTHOUGH I HAD TO APPLY MORE PRESSURE TO STOP, IT TOOK LONGER TO STOP. IT ROLLED TO A STOP. WHEN I GOT BACK HOME, I HEARD A HISSING SOUND COMING FROM UNDER THE DASHBOARD. MAZDA'S OWNER'S MANUAL REGARDING THE ENGINE LIGHT INDICATES 1.) THE FUEL TANK LEVEL BEING VERY LOW, 2.) POSSIBLE ELECTRICAL SYSTEM PROBLEM, 3.) EMISSION CONTROL PROBLEM, OR 4.) FUEL FILLER CAP IS MISSING OR LOSE. THE NEXT MORNING I DROVE THE CX-9 TO SEE IF TIGHTENING THE GAS CAP WOULD CORRECT THE ENGINE LIGHT. DURING THE DRIVE, THE BRAKING SEEMED DIFFERENT. I WOULD PRESS THE BRAKE, BUT THE VEHICLE WOULD ROLL TO A STOP INSTEAD OF STOPPING. WHEN I WAS APPROACHING A CAR STOPPED AT A RED LIGHT, I HAD TO PRESS THE BRAKE VERY HARD TO AVOID THE VEHICLE. I PARKED IT AND CALLED THE LOCAL MAZDA DEALER. AFTER THEY PERFORMED A DIAGNOSTIC TEST, THE BRAKE BOOSTER WAS DETERMINED TO BE FAULTY. I WAS CONFUSED ABOUT HOW A BRAKE BOOSTER AND AN ENGINE LIGHT CORRELATES. I'M ALSO TRYING TO UNDERSTAND WHY THE BRAKE SYSTEM WARNING LIGHT WAS NOT ACTIVATED SINCE THIS RELATES TO THE BRAKING SYSTEM. AFTER ADDITIONAL RESEARCH, I'M IN COMPLETE DISBELIEF THAT MAZDA IS AWARE, AND IT HAS NOT DECIDED TO ADDRESS THIS SAFETY ISSUE. PLEASE TAKE ACTION TO HAVE MAZDA RECALL THE BRAKE BOOSTERS TO ADDRESS THIS ISSUE SINCE IT'S AWARE THE PROBLEM IS AN EQUIPMENT/MATERIALS ISSUE.
BOTH REAR BRAKES LOCKED UP ON SEPARATE OCCASION WHILE DRIVING ON THE FREEWAY AT ABOUT 70 MPH. EACH TIME THE BRAKE ENGAGED THEMSELVES AND LOCKED ONTO THE DISK/ROTOR. THIS CAUSED THE PADS TO BURN UP AND PRODUCE A LARGER QUANTITY OF SMOKE. ON ONE OCCASION THE ROTOR BECAME RED HOT, FLAME WAS VISIBLE, LOTS OF SMOKE WAS BEING PRODUCED, AND IT WARPED ROTOR. EVERY TIME IT OCCURRED I STOPPED THE VEHICLE AND TURNED IT OFF. AFTER THE RESTART OF THE VEHICLE THE BRAKES WERE NOT LOCKED BUT THE VEHICLE WOULD SHAKE AS NOW THE ROTORS WERE WARPED AN THE PADS WERE DESTROYED. I TOOK MY VEHICLE TO THE MAZDA DEALERSHIP AND THEY INFORMED ME THAT I NEEDED NEW PADS, I DID BUT IT WAS DUE TO THE REAR BRAKES LOCKING UP ON THEIR OWN. I GOT THE PADS REPLACED AND 6 MONTHS LATER IT HAPPENED AGAIN. THIS TIME I RECORDED A VIDEO ON MY PHONE AND SHOWED THE DEALER SHIP WHAT I EXPERIENCED AGAIN. THIS TIME THEY INFORMED THAT I NEEDED, NEW BRAKE PADS(AGAIN), ROTORS, AND PISTON BUT THEY DID NOT ADDRESS WHAT IS CAUSING THE REAR BRAKES ONLY TO LOCK UP ON THEIR OWN CREATING EXCESSIVE WEAR AND DAMAGE TO THE BRAKE COMPONENTS. SOMETHING IS AND CONTINUES TO ENGAGE MY REAR BRAKES. IT LAST OCCURRED ON 10-04-19 AND IT HAS ONLY BEEN 3 DAYS SINCE THE MAZDA DEALER REPLACED THE DAMAGED PARTS AND UNDER HARD BRAKING THE VEHICLE CONTINUES TO SHAKE WHICH ARE EARLY SIGNS OF WHAT HAPPENED BEFORE, SO ITS ONLY A MATTER OF TIME BEFORE IT OCCURS AGAIN.
I WAS DRIVING ON THE INTERSTATE AND THE TPMS WARNING CAME ON. I PULL OFF THE INTERSTATE AND PARK. THERE IS SMOKE COMING FROM THE RIGHT REAR WHEEL AND THE CENTER OF THE WHEEL IS EXTREMELY HOT, TOO HOT TO TOUCH. I CAN FEEL THE HEAT FROM ABOUT A FOOT AWAY. THERE IS METAL PINING AND GROANING AS IT COOLS DOWN, THE TIRE IS WARM, BUT NOT AS HOT AS THE CENTER A THE WHEEL. THE LEFT REAR WHEEL IS COOL TO THE TOUCH, AS ARE THE FRONT WHEELS. I TOGGLE THE ELECTRONIC PARKING BRAKE A FEW TIMES AND AFTER THE WHEEL HAS COOLED DOWN I DRIVE ON. THE PROBLEM DID NOT OCCUR AGAIN IN THE LAST 60 MILES, HOWEVER, THE RIGHT REAR WHEEL NOW MAKES A NOISE WHEN BRAKES ARE BEING APPLIED CONSISTENT WITH THE ROTATION OF THE WHEEL.
ONE MILE FROM HOME THE SMART BRAKE SYSTEM MALFUNCTION & FRONT RADAR SYSTEM MALFUNCTION WAS DISPLAYED. CAR WAS SHAKING AND ACTING AS IF THE EMERGENCY BRAKE WAS ACTIVE WHILE THE CAR WAS IN MOTION. CAR WAS SLOW TO ACCELERATE. HAD I BEEN ON THE INTERSTATE I COULD HAVE BEEN REAR-ENDED. PULLED OVER TO TURN THE CAR OFF AND BACK ON. CAR WAS OKAY THE REMAINDER OF MY 20 MILE DRIVE.
Complaints are unverified consumer reports submitted to NHTSA. A high complaint count may reflect vehicle popularity, not defect severity. Data sourced from NHTSA public records.
Data synced from NHTSA on Apr 25, 2026