What 125 owners told NHTSA about the 2018 Mazda Cx-90 Phev

The liftgate (trunk) opens sporadically. The system keeps trying to open the truck and it's causing a parasitic drain on my battery. I was stranded 2 hours from my home due to this. My trunk would sporadically beep three times, that is the only warning I received. There are safety recalls for other year of Mazda cx-9 but not my specific even though I am having the same issue.

NHTSA ODI 11725165

Passenger seat heater either had a grounding issue or shorted out, causing to seat to start smoldering and catching fire, destroying the seat. There has been recalls and lawsuits for this specific issue on this model in other years, but not for this model year.

NHTSA ODI 11713860

[XXX] 2018 MAZDA CX-9 GRAND TOURING 89014 MILES Date: 9/11/2025 To: Mazda North American Operations Attn: Customer Experience Center 7755 Irvine Center Drive Irvine, CA 92618 USA Subject: Formal Complaint Regarding Safety and Technical Issue – 2018 Mazda CX-9 Dear Mazda Customer Experience Team, I am writing to formally lodge a complaint regarding a serious safety and technical issue I have experienced with my 2018 Mazda CX-9. After a recent inspection conducted by Mazda Koch 33, it was brought to my attention that the engine wiring harness is defective and may potentially cause a fire or result in burns, posing a severe safety risk to me, my passengers, and others on the road. This issue is deeply concerning and unacceptable, especially considering Mazda’s reputation for reliability and safety. A fault in the engine wiring harness, particularly one that has the potential to ignite or burn, should be treated with the utmost urgency. It is troubling that such a critical component could present such danger. My vehicle has been serviced and maintained regularly, and I was not made aware of any recall or technical service bulletin that addressed this defect until the inspection. Given the nature of the defect, I believe this may be a manufacturer defect, and I request that Mazda: Immediately investigate and confirm whether this issue falls under an existing recall or known defect. Take full responsibility for replacing or repairing the affected wiring harness at no cost to me. Provide assurances in writing that my vehicle is safe to operate. Offer compensation or a loaner vehicle if the repair process renders my vehicle unusable for any period of time. Please consider this a formal request for immediate corrective action. I expect a prompt response within 10 business days of the date of this letter. If I do not receive a satisfactory resolution, I will be compelled to escalate this matter further through consumer protection agencies, such as the INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11686751

my 2018 MAZDA CX-9 safety issue SCBS / SBS, LAS / LDWS, MASTER AND/OR HBC WARNING LIGHTS Forward sensing camera (FSC) stops functioning cause my car run rough even depress accelration and those light came on dashbaord -Forworad smart city brake support malfunction -smart brake system -front camera sensor malfunction

NHTSA ODI 11685844

I am submitting this recall request because my vehicle has experienced repeated incidents of a serious safety issue. While driving—most often on the highway—a warning appears that says “Smart System Brake Malfunction.” Immediately after, the car begins braking on its own without driver input. This has happened multiple times and, based on online reports, it appears to be affecting many Mazda vehicles across different models and years. Each time, I have been forced to pull over, turn off the car, and restart it to temporarily resolve the issue. This is extremely dangerous, especially at highway speeds, as it creates a high risk of rear-end collisions and sudden loss of vehicle control. When reported to Mazda, the concern was dismissed as a “sensor issue,” but the repeated nature and widespread reports suggest a potential systemic defect that requires urgent investigation and recall.

NHTSA ODI 11682407

Infotainment screen (LCD) of Mazda CX-9 2018 has developed what looks like discoloration/scratching/frost in corner of screen about 2 years ago and it is continuing to spread over last 6 months. This screen is used for hands-free bluetooth/calling (which is now the law in Iowa) and the back-up camera which allows for safe backing. If screen is unreadable, these safety functions cannot be performed properly. I take my car into Mazda dealership for maintenance/oil changes and it has never been addressed as an issue, but I'm concerned.

NHTSA ODI 11673548

There is a recall for Mazda 2016-2017 infotainment screens where they will show signs of cracking under the plastic and the screen will reboot. I have a 2018 CX-9 and Mazda corporate acknowledged the issue but only offered 15% of the price of a replacement part instead of replacing it. They said my VIN was not part of the original recall. I informed them this was a safety concern and then did not care. Case number - [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11536484

The infotainment system screen has developed several cracks in the upper left-hand corner of the screen. Often time these cracks look like spiderwebs or frost --it's commonly referred to as "spider cracking." This is the second time my vehicle has had this issue. At the present time, the cracks are contained to the upper left-hand corner of the screen, but they are getting larger. The vehicle has been inspected by my local MAZDA dealership and I'm awaiting a resolution. As I understand, this is a known issue with 2016-2017 model years and a TSB has been issued for these years. MAZDA should extend the TSB to 2018 and beyond.

NHTSA ODI 11510436

The main infotainment display randomly exhibited "spider cracking" which obstructs the view of the material being displayed within the screen. It is unsafe because the operator is unable to see maps, time, locations, controls, reverse cameras, etc. All of these are displayed in the screen and, due to the manufacturing defect, the operator is distracted by straining to see what is displayed behind the cracking. This is a well documented issue plaguing Mazda vehicles. Mazda has admitted it as defective, and are fixing the problem in the 2016-17 models. However, the 2018 model (which has the same screen as the 2016-17) is being refused. The fix needs to be extended to the 2018 model and beyond since it iw clear this it is still a widespread issue. It is well documented that once the cracking starts, it quickly spreads to the entire screen if not repaired, causing even more danger to the operator who will be distracted while attempting to see the display behind the screen.

NHTSA ODI 11508426

Mazda has refused to admit and repair a clearly defective screen, affecting visibility of the camera system, navigation, climate controls and infotainment. Pictures attached are several months old and the issue continues to get worse. The dealer says "corporate won't cover it", corporate customer service will not respond to repeated attempts at contact other than a generic "your VIN is not covered". Service alert direct from Mazda and pictures of my screen showing the EXACT issue are attached. For a $40k+ vehicle with less than 30k miles on it (less than 20k when the issue started), this is unacceptable. Please hold Mazda accountable.

NHTSA ODI 11481586

When I shifted into reverse the back up camera wouldn’t come on and instead a screen that said check your surroundings stayed on the screen. I reset it using the 3 button reset method and it came back on. Drove it to the grocery store, and then it sat in my driveway for 3 hours. When I went to go back in to town, the car was completely dead. No power whatsoever. We tried jumper cables and those didn’t work. Finally tried a battery charger and after an hour of charging it finally came back on. A car this new shouldn’t be having these issues.

NHTSA ODI 11418943

CAR SHOWED IGNITION ON WHEN THE CAR WAS TURNED OFF. SAME DAY WHILE DRIVING ON HIGHWAY CAR ENGINE REVVED FOR NO REASON. ALSO WHEN SOMEONE GOT OUT OF PARKED CAR IT SAID NO KEY DETECTED BUT CAR WAS STILL TURNED ON AND KEY WAS RIGHT BESIDE ME.

NHTSA ODI 11233692

CPSC: THE MANUFACTURER SELLS A SMART CAR SEAT. *DT THE CONSUMER STATED THE CYBEX SIRONSAFE 2.0 CAR SEATS PLUG INTO THE VEHICLES OBD PORTS. THE CAR SEATS BOTH INDIVIDUALLY DRAINED THE BATTERY OF THE VEHICLE. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE BUT, DID NOT OFFER ANY ASSISTANCE. *JS

NHTSA ODI 11207796

THIS VEHICLE IS HAS BEEN ON LEASE FOR 1 YEAR AND HAS LESS THAN 4000 MILES ON IT. INITIALLY WHILE ATTEMPTING TO START THE VEHICLE THAT HAD BEEN PARKED OVERNIGHT IT GAVE THE FOLLOWING WARNINGS: - KEYLESS ENTRY MALFUNCTION - CHARGING SYSTEM MALFUNCTION - VEHICLE OVERHEATING - BATTERY MALFUNCTION THE CAR WOULD NOT SHUT OFF UNTIL I HELD THE START/STOP BUTTON IN FOR ROUGHLY 20SECS. THE DEALER SERVICE CENTER TOOK THE CAR AND TOLD US THE BATTERY HAD A LOW CHARGE, CHARGED IT AND RETURNED IT. SEVERAL WEEKS LATER WHILE THE VEHICLE WAS IN MOTION WITH 2 ADULTS AND 2 CHILDREN ON A CITY STREET TRAVELING AT ABOUT 20MPH IT GAVE THE FOLLOWING WARNINGS: - KEYLESS ENTRY MALFUCTION - CHARGING SYSTEM MALFUCTION - VEHICLE OVERHEATING - BATTERY MALFUNCTION - PULL OVER TO SAFETY AT THIS POINT THE VEHICLE WAS STILL IN MOTION AND THE STEREO, HVAC, AND POWER STEERING CUT OUT. I WAS ABLE TO PULL THE VEHICLE OVER BUT AGAIN HAD TROUBLE SHUTTING IT OFF. I HAD TO HOLD THE START/STOP BUTTON FOR 20-40SECS. THE CAR WAS TOWED TO THE DEALER SERVICE CENTER. WE WERE TOLD BY THE SERVICE CENTER THAT A LOT OF 500 VEHICLES OF THIS YEAR AND MODEL HAD AN ENGINE HARNESS DEFECT THAT NO RECALL HAD BEEN ISSUED FOR BUT THEY WERE AWARE OF DEFECT AND HAD A FIX FOR IT. I FEEL I WAS LUCKY THAT I WAS ONLY TRAVELING 20MPH WHEN THE POWER STEERING CUT OUT. IF I HAD BEEN TRAVELING HIGHWAY SPEEDS ON A BEND THE SITUATION COULD HAVE BEEN TRAGIC AND I HAD MY CHILDREN IN THE CAR. CURRENTLY, BASED ON WHAT I'VE BEEN TOLD BY THE DEALER SERVICE AND SALES MANAGERS THERE ARE POTENTIALLY HUNDREDS OF OTHER 2018 CX-9S WHICH COULD EXPERIENCE THIS SAME MALFUNCTION WHILE IN MOTION.

NHTSA ODI 11192600

WHILE DRIVING THE VEHICLE THE CAR TO AN ABRUPT STOP AND I HAD NO CONTROL. THE DASHBOARD LIT UP WITH ALL TYPES OF WARNINGS AND HEAT WAS COMING FROM THE FRONT OF THE CAR.

NHTSA ODI 11142801