CarComplaints.com Notes: The only area of real concern for 2010 Mazda CX-9 owners is the brake booster.

In 2014, Mazda extended the warranty on the 2007-2013 CX-9 brake booster to 7 years / 90,000 miles. However this extended warranty has expired, so buyer beware.

This Mazda CX-9 brake booster failure isn't terrible in terms of repair cost — it "only" costs $550 average to fix. However it is a safety issue when the brake booster fails as it increases stopping distance. Owners have reported having to stomp on the brake pedal, & crashes/injuries have been reported due to this CX-9 brake booster defect.

5.6

fairly significant
Crashes / Fires:
0 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
15,581 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2010 Mazda CX-9 engine problems

engine problem

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2010 Mazda CX-9 Owner Comments

problem #7

Jan 012012

CX-9

  • 30,000 miles

A D V E R T I S E M E N T S

Took my car to dealer 2-3 times for the brakes, way before my warranty was any where near expiring, because I kept hearing a grinding sound. They kept telling me nothing was wrong, that my brakes had some gravel on them and they just cleaned them. I don't travel on dirt roads or anything, city roads/highways. No out of town travel at all, actual only in town travel, home/work. My 2nd concern is, while driving sometimes my speed seems to shift, as if the gears are shifting. 3rd concern is, I received a recall notice, don't recall what it was about but I took it to the dealership and I was told they done that work last time I came in but I don't believe it was done, since they haven't been honest with me before. They didn't even look at the letter. If I recall correctly brake complaints/ service started 2011 or 2012 to 2014....

- Little Rock, AR, USA

problem #6

Mar 262014

CX-9 6-cyl

  • miles
I was driving around a sharp bend in the road. I pushed down on the brake peddle to slow down and the car kept accelerating at the same speed. The car never slowed down and I had to take the corner at a unsafe speed. I drove to the next street and tested the brakes and they worked fine? very scary incident.

- Galloway, NJ, USA

problem #5

Nov 302013

CX-9 6-cyl

  • 25,068 miles
While driving my 2010 Mazda Cx-9 approximately 65mph on interstate 270S in Maryland, I pressed the gas pedal to accelerate in an attempt to pass several vehicles who were traveling in the right hand lane. Once I felt that I had enough additional speed to successfully pass the vehicles, I released the gas pedal and noted that the car continued to accelerate. I attempted to apply my brakes, but they would not slow the vehicle. After several unsuccessful attempts to apply my brakes, I searched for a safe place to continue traveling as my vehicle continued to accelerate, noting I would need to shift into neutral and move into the median. Luckily, after numerous repeated attempts, my brakes finally engaged and slowed the vehicle. I feel this is a manufacturer's defect that could ultimately lead to a fatality. I am too scared to drive the vehicle at this point in time.

- Frederick, MD, USA

problem #4

Feb 202012

CX-9

  • miles

A D V E R T I S E M E N T S

The first time I experienced this terrifying ordeal was in November of 2011. Since then, I have had it happen two more times. The car accelerates of up to speeds of 90 mph without warning. All 3 incidents have happened on the highway. The brakes slow it down, but do not stop it. All 3 times, I've been lucky enough to get the car to the shoulder and ride down the median, pushing the emergency break in and at one point pushing it into park. Mazda knows about this. Therefore they are liable. Mazda will tell you it's a throttle problem, they will tell you there is no wear on the brakes....well, that's because when the car does this unexpected acceleration, the brakes only go part way..almost like pushing against air. This is a serious problem with the computer and possibly throttle combined. My car is not fixed, it's also doing other stuff. Mazda wants me to keep this car and drive it. They are giants, so the little person like me does not matter to them it's the $$$$. but when someone dies, it will cost them $$$$$$$$$$. there needs to be a recall. I hope more people come forward. It could save your life or/and someone you love and other drivers on the road who are in danger of you hurting/killing them. My Mazda dealership have wonderful people who work there. They are very unhappy with Mazda not taking care of this problem. I want to make this clear, it's Mazda Corp that is aware and doing nothing and they hold the Mazda dealers hostage.

- Virginia Beach, VA, USA

problem #3

Feb 172012

CX-9

  • 18,000 miles
The contact owns a 2010 Mazda Cx-9. while driving approximately 10 mph, the vehicle uncontrollably accelerated into oncoming traffic. The brakes were applied repeatedly when suddenly the vehicle came to a stop. The vehicle was towed to an authorized dealer for diagnosis where the technician was unable to locate the problem. The manufacturer was notified of the unintended acceleration failure. The approximate failure mileage was 18,000.

- Haverstraw, NY, USA

problem #2

Feb 242012

CX-9

  • 17,000 miles
The contact owns a 2010 Mazda Cx-9. the contact was driving 50 mph when the vehicle surged forward uncontrollably. The contact was able to eventually stop the vehicle and the vehicle was taken to an authorized dealer where they were unable to diagnose the failure. The vehicle was not repaired. The manufacturer was made aware of the failure and offered no assistance. The failure mileage was 17,000. The VIN was unavailable.

- Haverstraw, NY, USA

problem #1

Sep 182011

CX-9

  • 19,000 miles
Was driving on I-495E in Maryland between exits 28 and 29. Changed lanes and put foot down on gas pedal to accelerate. Suddenly felt like gas pedal was stuck and that braking could only slow but not stop acceleration. Moved over a few lanes to right shoulder and after continued failure of brakes to stop acceleration (and considerable engine torque) began to apply emergency brake. Slowed acceleration further but still could not bring car to a full stop. Finally put car into neutral and came to a stop. Had towed to nearest Mazda dealer, yet after several days of testing they found nothing wrong with car and could not replicate. Claimed manufacturer had no record of similar problems with this model. Only thing they could think of was that all-weather floor mat might have slid over pedal and kept it depressed.

- Washington, DC, USA

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