Which parts fail
Components named in complaints (accelerator pedal, throttle, sudden acceleration, cruise control).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2011 Chevrolet Impala owners, lightly cleaned up (personal details are redacted by NHTSA).
After getting into my parked car and starting it, the Stabilitrak warning message came on my display. This is the 2nd tike that this occurred. The first time it occured, my mechanic diagnosed it as a failed throttle body, which I replaced myself, (easy removal/installation). Now, a couple of months later, it occurred again. After doing some online research, it seems as though the position sensor on the accelerator pedal may be at fault. A lot, if not most cars today have a "fly-by-wire" system which replaces cables and such with sensors and motors. So, the accelerator, (gas), pedal controls the movement of the butterfly valve on the throttle body by sending a signal to the motor. I'm going to replace that... about $140 or so. I saw a YouTube video and the removal/installation is fairly easy. A lot of people are having this issue; maybe a recall is needed?
Brake assist, traction control, stablitrack, and ABS lights continually coming on. When breaking while making a turn the breaks slip or give and then suddenly grab hold causing a grinding sound. Car wobbles while these lights are on causing a noticeable change in stability and control.
Dec 2013 vehicle hit pot hole while braking at approaching intersection, after that warning lights started flashing ABS brakes/tract control/stab control, I was unable to brake, then shut down. Since then temp gauge went bad n was replaced. The 3 above dash warning lights continued intermittently, worse when it rained. At take offs n turns car would jar n ABS brake system would pulsate(grabs). Hub/speed sensor was replaced, this did not help. Accessory outlets, when contained w a charger, doesn't maintain contact w power source (such as disconnection/loose connection), causing power surge resulting in 2 iphones to have bad aux ports. …
My wife was driving home from work going 65 down a very busy highway. All of a sudden the reduced engine power light, check engine, stability control off, and traction control lights came on. The car begin to loose speed. Luckily she was able to get over to the right shoulder without anyone hitting her. When she got to the shoulder the car was running really rough. She turned it off waited a few minutes and restarted it. It then ran fine but the check engine light remained on. She made it home and was scared to drive it again. I took it to work last night and made it about halfway to work and it did the exact same thing except I was able to get it to maintain 45mph. When I came to a traffic light though the engine was running so rough the car was very hard to stop. I made it to work. When I came out to go home the first stop light I came to it started acting up again. …
While at a complete stop, when the vehicle is in drive, as I attempt to push the accelerator to drive through an intersection, the car will stall for a second, make noise that sounds like a whine, and then jump forward like it's having a difficult time finding first gear. The vehicle does this every so often, but not all the time. I've taken it into car x, my local Chevrolet dealership, and another local Goodyear tires dealer, but nobody has any idea what I'm talking about. The vehicle has been hooked up to a computer and technicians have looked at it, but just scratch their heads. There is even a forum online regarding this happening with other Chevy Impala owners [redacted] and owners seem to put lots of money into the issue but with no resolve. ** the issue seems to remedy itself when I turn off the traction control. …
As I was driving on the straight highway at about 70 MPH I let off the accelerator due to a car ahead of me driving under speed limit as I put pressure on the pedal it sped up but felt a slight hesitation, I thought not much of it until I see a 18 wheeler coming up fast , I put a little more pressure on accelerator to by pass the slow car in the right lane as I did this I felt my gas pedal wobble to the side w 18 wheeler still behind me I tried to speed up and make it to safety because I knew something wasn't right , just as I get back in the right lane I felt the pedal give as if it just broke off ... I kept driving to catch the next exit and to get off of the two lanes and get myself to safety but it wasn't catching speed I panticked pushed my energy lights on and kept pushing the pedal for it to go still not much help .. …
Car gets service stabitrack, traction control and ABS warning on dash. Replacing wheel hubs with sensors does not fix this issue. Sometimes the car will want to apply brakes while driving or reduce engine speed. I have been through many forums with people reporting the same issue on the same car and through multiple years of manufacturing. From the research I have done in the last few days it looks like hundreds of owners have reported this issue but Chevrolet is not doing anything to correct it. Not sure at this point if it is the wiring harness causing the problem or if this could be something with the computer that controls the stabitrack, ABS and traction control. If cars are loosing power and or the brakes are being applied with out driver control this can lead to dangerous driving conditions for the car owner passengers and everyone else driving on the same road. …
Driving at approx 35 MPH, my car showed service stabilitrack / service traction control / vehicle in reduced power. I did have reduced power, could not go any faster than 15 or 20 MPH. I continued down the road another block and without warning, the car shuts down while going down a slight grade,, which cause steering to become very hard to use along with little to no braking, I ended up going thru a stop sign at the bottom of the grade because of lack of braking power, luckily no vehicles were coming, I got the vehicle stopped, and looked at the display, it said ignition disabled, service throttle. By the vehicle shutting down that is a safety issue, the vehicle should never shut down making steering and braking almost impossible, if it finds an issue with the throttle, it should just disable the throttle so I can steer and brake without problem. …
I was driving on a highway going approximately 55 MPH, the engine light, stability control light, and reduced engine power light came on at the same time. Within two (2) minutes of the dash warning lights coming on, the car completely shut it self off while I was driving in the left lane going 55 MPH. I lost steering, had no power, or braking. I threw the car in neutral, in an attempt to get it started it while I was in motion with no power. The Impala didn't even try to turn over. The car wasn't responding because the power steering / braking was not responding. The Impala went into "limp mode" without warning. I let the car cost for a while until I could find a safe spot to apply the emergency brake. I really had to muscle the steering wheel with some significant force to get it to turn. I have never had any problems with this vehicle before this issue. …
2/17/2015 was the second event. I was driving approx- 65 MPH up a mountain when my electronic display panel showed stabilitrack/service traction control/vehicle in reduced power. As the power suddenly reduced I lost power steering control and brake function. Since I was traveling at a up hill grade, I was barely able to jerk the steering wheel enough to roll across the lane of traffic beside me to the side of the road. I wasn't able to get out of the road completely and was almost hit by a logging truck. After removing the keys from the ignition for a few minutes, I restarted the car without any hesitation. The engine light still remains on at this time. I did contact OnStar and have them run a diagnostic test which revealed a problem with supposed fuel system. I have not taken it to a dealership yet. …
Acceleration complaints in other Impala years
Frequently asked questions
How common are acceleration problems on the 2011 Chevrolet Impala?
NHTSA has 69 complaints about the speed control & acceleration of the 2011 Chevrolet Impala, 14% of the model year's 505 complaints. The component named most often is accelerator pedal (3 mentions).
Is there a recall for 2011 Chevrolet Impala acceleration problems?
No. NHTSA lists no speed control & acceleration recall for the 2011 Chevrolet Impala, though it has 2 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2011 Chevrolet Impala acceleration problems start?
Half of the complaints with a recorded mileage happened before about 65,000 miles, and 5% before 25,000 miles.
Is it dangerous?
Owners linked 0 crashes, 1 fire and 0 injuries to speed control & acceleration problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.