On 12/21/16 while merging onto interstate 10 in tucson, AZ, the vehicle was going approximately 65 mph when a "engine power reduced" sign popped up, the vehicle slowed down to 30 mph without warning and shifting down through all gears nearly red lining the rpms and causing an rear-end collision. Was able to move the vehicle off the freeway and took it into local auto-zone for testing. The test came back as a "throttle sensor malfunction". the vehicle now doesn't feel safe to drive, and will not accelerate over 45 mph without shaking and feeling like the transmission is going to give out. Called the local Chevy dealership and was told the cost was going to vary between $400-1,000 with a $100 test fee up front. I've also read numerous similar issues online from people driving Chevrolet Impala from 2006-2016. The car feel very unsafe to drive and I feel it could be a death trap as there is no control over when the vehicle will choose to decelerate without warning. There has been no mechanical issues before this incident, and the vehicle has been through numerous mechanical maintenance up-keeps that were recommended by service managers.

- Marana, AZ, USA

My Impala 2014 suddenly says 'service stabilitrak' in the display and the engine power drastically reduces. I have see this in forums that is a common issue with GM cars and it happened to me couple of times. This is a very dangerous issue when happens at freeways or any faster traffic routes.

- Snoqualmie, WA, USA

The contact owns a 2014 Chevrolet Impala. The contact stated that while driving at 68 mph with the cruise control, the brake pedal was depressed which deactivated the cruise control setting. Upon resuming to 68 mph, the contact hit resume on the cruise control, the vehicle accelerated to 90 mph without warning, and the contact turned the cruise control off to stop the acceleration. The vehicle was taken to a dealer but was not diagnosed or repaired. The failure recurred on another occasion. The manufacturer was not made aware of the failure. The failure mileage was 18,000. Updated 03/09/16

- Osceola, IA, USA

When decelerating at a red light which turned green, attempted to accelerate with no throttle response, even when pushed to the floor for approximately 2 seconds or more (several similar incidents). Second incident, car stalled at a slow speed. Third incident, after accelerating the engine rpms stay reving high after taking foot off the gas for several seconds, and this has happened on several occasions and as recently as 9-16-15. These incidents all occured before and after a complete GM dealer reprogrammed the computer.

- Salem, VA, USA

On a couple of different occasions I have been stopped at a stoplight or stop sign. When the gas pedal is pressed to accelerate, there is hesitation by the vehicle to accelerate causing the vehicle's act of acceleration to occur separately from the act of pressing the gas pedal.

- Northlake, IL, USA

Forward collision avoidance system inappropriate activation on several occasions at different locations. There were no other vehicle in front. There were three beeps/red light flash on windshield. The cruise control would deactivate and car would decelerate by three to five mile. The tail lamps are not activated to warn drivers following. This is my second complaint the dealer solution is to turn off the feature. It work when it should the inappropriate activation is a nuisance.

- Detroit, MI, USA

While driving on Texas highway 287, southbound, my anti-collision alert system activated. It sounded a loud beeping, followed by a full application of all brakes. Startled, I was able to apply the accelerator pedal to resume my speed. Approximately 5 miles further, the incident repeated it self. During the first incident, there were no vehicles in front of me, none. The road was dry, straight and free of any obstacles. There was no traffic behind me. The second time the car automatically locked up my brakes, there was a car behind me, but he was able to swerve and avoid rear-ending me. Again, there was no traffic of any type ahead of me and the road was flat, dry and straight. Again I was able to apply the accelerator pedal to regain control of the car and pull over to the side where I.shut off the engine. I restarted the engine and proceeded to my destination in springtown, Texas without further incident. I took the car to the dealership the next week for a diagnostic search and repair of the incident. They had the car for three days and told me nothing was wrong with the car. I'm filing this complaint, because I believe that this is a potential deadly threat to me, my passengers, or other drivers.

- Livingston, TX, USA

The contact owns a 2014 Chevrolet Impala. The contact stated that while driving 35 mph, the vehicle surged with hesitation. The failure recurred whenever traveling at the speed of 35 mph. The vehicle was taken to an authorized dealer, who stated that the vehicle functioned as designed. The manufacturer was not notified of the problem. The approximate failure mileage was 4,000. The VIN was unavailable.

- Dearborn, MI, USA