A week ago Sunday I was driving my 2010 CX-9 (around 19K) on the interstate to pick up my son from a birthday party. I changed lanes, put my foot on the gas pedal to accelerate, and suddenly felt surge of acceleration. Tried to brake, and it slowed the car some, but the engine torque was considerable, it felt like trying to rein in a wild bronco. Realized that I was experiencing unintended acceleration. Made sure I was pushing down on brake and not gas pedal so I could rule that out. At that point, felt I had to move over to shoulder as fast as possible. Did so and began applying emergency brake (I know that was mistake now). It slowed car more but still wouldn't come to a stop. Finally, put car in neutral and that stopped the car.
Had car towed to nearest Mazda dealer and they kept it for almost a week but couldn't find anything wrong (no electronic record left) and couldn't replicate. Only thing they could think of was that my all-weather mat had slid forward and depressed gas pedal. I reported to NHTSA but so far haven't found anything reported online about similar problems with this make and model. So I picked car up yesterday, but I am still very concerned that this will happen again, God forbid with my children in the car or with my wife driving.
Can anyone think of other suggestions of what I might do?
Hi - this is several years later, but I had two similar incidents in fall 2015 with a 2008 Mazda CX-9 Grand Touring. I've had it for almost 4 years, no issues until recently.
In the first incident, I started the car in our driveway but hadn't yet put it into gear when the engine revved really fast and stayed there. I wasn't pressing the accelerator, and the mat is almost impossible to get stuck down there with the hook keeping it in place.
In the second incent, I was backing out of a spot in a grocery store parking lot when the engine revved and we went backwards fast. I was able to apply the brakes, stop, and shift (into D, should have chosen N but it happened very fast), and the engine went back to normal revs after that.
Two trips to the dealership, including a call to Mazda national, and no diagnosis. I also reported the issue to NHTSA in late Dec 2015. We're now getting rid of the car, which is really disappointing because it's a financial loss and also very nice to drive.