Home · 2018 Mazda Cx-90 Phev · Complaints

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

These are the actual owner complaints behind this car’s reliability verdict, filed with the federal government, unedited. They’re unverified reports, not confirmed defects: read them as leads for your pre-purchase inspection, not a diagnosis.

All (125)Crash / fire / injury (5)Engine (73)Electrical system (15)Transmission & drivetrain (13)Brakes (11)Fuel system (7)Driver assistance (4)Backup camera & sensors (3)Steering (3)Visibility & wipers (3)Airbags (2)

4 of 125 complaints match · Driver assistance · clear filters

Aug 22, 2025Electrical systemBrakesDriver assistance

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

Apr 15, 2025BrakesDriver assistance

1. The navigation has a frosted crackle appearance framing the screen. It is difficult to read the navigation when needed. I know this has happened to other models of this vehicle and those were recalled and covered. 2. The brake senor keeps going off stating "SMART BRAKE SYSTEM MALFUNCTION". This goes off repeatedly while driving. 3. Then a second message pops up and reads "FRONT RADAR SENSOR SYSTEM MALFUNTION".

NHTSA ODI 11654693

Dec 7, 2022LightsBrakesDriver assistance

I keep getting a automatic emergency braking malfunction alert

NHTSA ODI 11496403

Dec 8, 2017Driver assistance

I PURCHASED A NEW MAZDA CX-9 IN SEPT 2017 BECAUSE IT HAD THE HIGHLY TOUTED SMART CITY BRAKING SYSTEM FOR WHICH I PAID THOUSANDS EXTRA. I HAD HAD A PREVIOUS REAR END COLLISION AND WANTED TO BE SURE THIS SYSTEM WOULD AT LEAST WARN ME. I SET UP SOME CARDBOARD BOXES WRAPPED IN ALUMINUM FOIL. I SLOWLY (10 MPH) DROVE THE CAR INTO THEM WITHOUT TOUCHING THE BRAKE OR ACCELERATOR. THE CAR DID NOT SLOW DOWN OR WARN ME.(I TRIED SENDING A VIDEO TO YOU FROM MY IPHONE WHICH MAY NOT GO THROUGH) I MADE AN APPOINT TO REPAIR THIS OBVIOUS FACTORY DEFECT AND SIGNIFICANT SAFETY ISSUE. THE SERVICE MANAGER AT OLYMPIA LINCOLN /MAZDA(AND PUYALLUP MILAM MAZDA) REFUSED TO REPAIR IT THEY STATED AND SHOWED ME A PRINT OUT FROM MAZDA FACTORY THAT FORBIDS REAL TIME TESTING AND STATED THAT IF THE TROUBLE LIGHT IS NOT ON THEY AREN'T ALLOWED TO REPAIR OR REAL TIME TEST IT. I THINK THAT THE FACTORY IS AFRAID OF DEALING WITH A MASSIVE SAFETY RECALL. TO COMPOUND THINGS THE ACTIVE LIVE TRAFFIC DISPLAY DOESN'T WORK EITHER WHICH MAKES MATTERS WORSE SINCE I CAN'T SEE WHERE AN ACCIDENT HAS OCCURS IN REAL TIME. I UNDERSTAND ITS DEFECTIVE IN MOST MAZDAS WITH NAVIGATION IN 2016 AND BEYOND. THE IS A CLASS ACTION LAW SUIT STARTING TO BE FILED ABOUT THIS. *BF CONSUMER STATED REGARDING DEFECTIVE AUTOMATIC BRAKING SYSTEM ON 2018 MAZDA CX-9. I HAVE NOT HEARD BACK AFTER FILING THIS COMPLAINT 2 MONTHS AGO. UPDATED 8/24/18*JB

NHTSA ODI 11053492

Working with the data? Download all 125 complaints as CSV · fetched from NHTSA July 18, 2026

How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your pre-purchase inspection list. Back to the full 2018 Mazda Cx-90 Phev verdict →