2021 Mazda CX-9 Vehicle speed control Problems
- Complaints
- 3about this part
- Share
- 8%of 40 total for the year
- Median mileage
- 53,186miles
- Trend
- Not enough dataFewer than 15 complaints, too few for a reliable trend.
NHTSA recorded 3 complaints about the vehicle speed control of the 2021 Mazda CX-9, 8% of the 40 complaints for this model year. Where a mileage was given, the median is 53,186 miles. 1 of these say a crash was involved, according to the filers.
Fewer than 15 complaints name this part, so treat the figures as a rough indication only.
Example complaints
Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.
“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 data from Mazda.”
NHTSA complaint #11755863, filed 2026-08“I entered the interstate normally, with no issues accelerating or merging. While driving at approximately 70 mph, in traffic, all three warning messages appeared on the instrument cluster at the same time: “Smart Brake System Malfunction,” “Driver Attention Alert System Malfunction,” and “Forward Smart City Brake Support Malfunction.” At the same moment, the vehicle began to lose speed. I pressed the accelerator pedal firmly. The speed continued to decrease instead of increasing. I could not accelerate at all. An exit was thankfully immediately available. …”
NHTSA complaint #11763863, filed 2026-09“The contact owns a 2021 Mazda CX-9. The contact stated that while accelerating quickly and entering the highway, there was no motive power to the vehicle. While crossing the highway in the right lane, driving at 65 MPH, the vehicle in front moved over; there was a parked vehicle. The contact was able to stop the vehicle before causing a crash. The driver was starting to accelerate, but there was no motive power when the accelerator pedal was depressed. The smart brake system malfunction message was displayed. There were no warning lights illuminated. …”
NHTSA complaint #11608556, filed 2024-08, 53,186 milesVehicle speed control: other model years
Other parts of the 2021 Mazda CX-9
21 complaintsOther or unknown
6 complaintsTransmission and drivetrain
5 complaintsBrakes
4 complaintsForward collision avoidance
4 complaintsAir bags
2 complaintsBack-over prevention (rear camera)
2 complaintsElectrical system
2 complaintsSteering
1 complaintsSuspension
1 complaintsTires
1 complaintsVisibility (wipers, defrost, mirrors)
1 complaints
← All problems reported for the 2021 Mazda CX-9
About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 30, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.
To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology