2021 Mazda CX-9: engine and transmission complaints
VERY HIGH COMPLAINT SIGNAL
61%
22 of 36 relevant owner complaints are about the engine, transmission or fuel system
61% of relevant owner complaints filed with NHTSA on the 2021 Mazda CX-9 are about the engine, transmission or fuel system. Well over half of everything owners reported is the drivetrain. That is a severe model-level pattern; every model year we track at this level has a documented failure behind it.
Worse than 81% of the 1,230 model years we track (2010–2023).
Excludes 2 airbag, lighting and seat-belt recall complaints that would otherwise mask the signal (unadjusted: 58%).
The percentage is each model year's drivetrain complaint share. No elevated signal describes the model year, not any one car; a well-kept example of a flagged model can still be the right buy, and any of these still needs an inspection.
What owners reported
POWER TRAIN,UNKNOWN OR OTHER,FORWARD COLLISION A10/16/2023CRASH1 INJURED
I was in a parking lot and came to a stop and placed the car in reverse to back into a parking space. The back-up camera was on and I began to back into the parking space when the car suddenly lurched/jerked forward and accelerated on its own. The car jumped the parking lot median strip and I hit a tree head on. I ha…
POWER TRAIN,VEHICLE SPEED CONTROL,ENGINE08/10/2026CRASH
The vehicle was parked stationary in the driveway with the engine running for 3-5 minutes with the A/C on. The vehicle then accelerated forward into my garage causing damage. Once I entered the vehicle, both the dash and shifter displayed park. Current TCU system internal failures have been reported from the pulling of…
ENGINE07/23/2026
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 daught…
Three of 22 drivetrain complaints. The full report shows more, with quotes about the engine in the car you are looking at first.
Recall campaigns on this model year (1)
SEATS:MID/REAR ASSEMBLY
Mazda North American Operations (Mazda) is recalling certain 2020-2021 CX-9 vehicles equipped with 60/40 split bench second-row seats. The left-side second-row seat may …
This does not say whether a particular car has an open, unrepaired recall. That depends on the VIN.
Before you buy a 2021 Mazda CX-9
Ask the seller whether the engine has ever been repaired or replaced, and whether the car has shown stalling, loss of power, rough idle, oil consumption or a check-engine light.
Drive it from a cold start and long enough to warm up. Many engine faults hide once the car is warm.
Get an independent pre-purchase inspection from a mechanic you choose, and tell them to focus on the engine.
1 recall campaign on this model year. Whether a specific car still has one open depends on the VIN; the report checks that.
Ask for service records. A engine already replaced under warranty is a different car from one that was not.
Have the VIN?Paste it and get the full report for that car. First report free, then a 30-day pass covers a whole car search.
Experimental model-level information. This is not a vehicle inspection, vehicle-history
report, financial advice or purchase recommendation. It describes patterns across a model year, not the condition
of any individual vehicle.