2021 Mazda CX-9 problems and owner complaints
Explore the records behind recurring owner reports.
Key facts
38 owner complaints analyzed
1 distinct recall campaigns
51,093 mi median reported failure mileage
Scope: 2021 model year. Data snapshot: . 4 complaints include usable failure mileage.
Most common problems
Engine is the most frequently named component, appearing in 20 of 38 complaints (52.6%). A complaint can name multiple components.
| Topic | Matching reports | Share of complaints |
|---|---|---|
| Braking behavior | 6 | 15.8% |
| Engine operation | 2 | 5.3% |
| Electrical and battery issues | 2 | 5.3% |
| Steering behavior | 1 | 2.6% |
Topic matches use published keyword rules. They describe mentions, including negations or comparisons, and do not confirm a diagnosis. Read the matching rules.
Component breakdown
Number of unique complaints naming each component. Top eight shown.
| Category | Count |
|---|---|
| Engine | 20 |
| Unknown Or Other | 6 |
| Service Brakes | 4 |
| Forward Collision Avoidance: Warnings | 3 |
| Power Train | 3 |
| Air Bags | 2 |
| Back Over Prevention: Sensing System: Camera | 1 |
| Back Over Prevention: Warnings | 1 |
Engine: 20; Unknown Or Other: 6; Service Brakes: 4; Forward Collision Avoidance: Warnings: 3; Power Train: 3; Air Bags: 2; Back Over Prevention: Sensing System: Camera: 1; Back Over Prevention: Warnings: 1
Reported problems by failure mileage
Complaint counts in mileage bands. These are not failure rates per vehicle or mile.
| Category | Count |
|---|---|
| Under 25,000 | 1 |
| 25,000 to 49,999 | 1 |
| 50,000 to 74,999 | 2 |
| 75,000 to 99,999 | 0 |
| 100,000 to 149,999 | 0 |
| 150,000 and above | 0 |
Under 25,000: 1; 25,000 to 49,999: 1; 50,000 to 74,999: 2; 75,000 to 99,999: 0; 100,000 to 149,999: 0; 150,000 and above: 0
50,000 to 74,999 miles has the most reports with usable mileage (2). 34 complaints have missing, zero or invalid mileage.
Complaints over time
Year the complaint was filed, not the vehicle model year or incident year. The snapshot year is partial.
| Category | Count |
|---|---|
| 2021 | 1 |
| 2022 | 11 |
| 2023 | 9 |
| 2024 | 10 |
| 2025 | 2 |
| 2026 | 5 |
2021: 1; 2022: 11; 2023: 9; 2024: 10; 2025: 2; 2026: 5
Pattern summary
Engine leads the component reports. Braking behavior appears in 6 complaint narratives. Engine operation appears in 2 complaint narratives. Electrical and battery issues appears in 2 complaint narratives. Use these patterns to inspect individual reports and prepare questions for a mechanic.
Calculated from recorded counts. An AI narrative has not been published for this selection.
Complaint evidence
Examples provide context, not a representative sample or a verified diagnosis.
Owner report 11397703 · 2021-02-24 (February 24, 2021)
AS I WAS DRIVING DOWNHILL WITH MINIMAL SNOW ON THE GROUND, I TAPPED MY BRAKES ABOUT 7 TIMES BEFORE THEY LOCKED UP. I WENT TO TURN TO STAY ON THE ROAD AND THE STEERING WHEEL WOULDN'T BUDGE CAUSING ME TO GO OFF THE ROAD, INTO AN EMBANKMENT. VEHICLE WAS GOING ABOUT 5-10MPH WHEN THIS OCCURED ON A CITY STREET.
Owner-reported narrative. 4,000 miles reported. Look up ODI 11397703 at NHTSA ↗
Owner report 11495745 · 2022-12-02 (December 2, 2022)
The driver side airbag did not deploy in a front end collision on the drivers side. When approaching a vehicle that had come to a sudden and complete stop, the brakes were applied hard to the Mazda CX-9 in order to stop, but after about 1 second they just totally let go and there was no braking at all and the Mazda continued to move forward until it slammed into the vehicle that was stopped. The MyMazda app sent a message that stated that there was a Brake System Malfunctiom which is exactly what occurred and caused the accident.
Owner-reported narrative. Look up ODI 11495745 at NHTSA ↗
Owner report 11505764 · 2023-02-06 (February 6, 2023)
The contact owns a 2021 Mazda CX-9. The contact stated that while driving at 60 MPH or exceeding 60 MPH, the vehicle would lose motive power and stall without warning. The contact stated that he would coast to the side of the road and the vehicle would restart after 2-3 attempts and regain normal functionality. The vehicle had not been diagnosed or repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 49,000.
Owner-reported narrative. 49,000 miles reported. Look up ODI 11505764 at NHTSA ↗
Owner report 11752508 · 2026-07-23 (July 23, 2026)
1) What component or system failed or malfunctioned: On 6/12/2026 While drive on the highway with our daughter in the car and we experienced a high speed stall. The engine failed and we lost power. We barely got the car of the highway and coasted into a parking lot. 2) Life threating for Father, Mother and daughter and other drivers on the highway. 3) The Mazda dealer stated they were unable to reproduced problem. The diagnostic report showed few random misfired on two cylinders 2 & 3. Autozone detected codes P0300 with Secondary DTCs…
Owner-reported narrative. Look up ODI 11752508 at NHTSA ↗
Owner report 11548334 · 2023-10-04 (October 4, 2023)
6/29/2023--Vehicle stopped suddenly with i-ACTIVESENSE system malfunction, Dynamic Stability Control malfunction, Engine malfunction, engine output reduced, Front radar sensor malfunction. Dealer said these faults due to bad battery--replaced battery per Service Manager [XXX] at Lakeland Mazda. 9/10/2023--Incident #2 with same faults as above with vehicle stopping suddenly at risk of creating a rear end collision. Lakeland Service Manager [XXX] now said that the faults are due to a faulty ERG valve. Lakeland Mazda and [XXX] are absolutely c…
Owner-reported narrative. Look up ODI 11548334 at NHTSA ↗
Owner report 11571147 · 2024-02-10 (February 10, 2024)
I was leaving for work when I put my personal items in the front passenger side first and then continued to walk around the car to get to the drivers side. Once I closed the passenger side door the car auto locked with all of my items in it including the key. Thankfully I had my cell phone in my pocket which has access to open the car via the Mazda app but it would not work. The spare key was not at the current location the car was at. We had to call someone out to unlock the car. This poses a safety problem because if I put my child in the bac…
Owner-reported narrative. Look up ODI 11571147 at NHTSA ↗