While vehicle is in foward driving motion on street or highway(20 - 70mph)out of no where, truck will have a quick second halt in its motion, as if someone pulled and released the emergency brake(see attach recording) all I feel is a sudden jerk which its intensity depends on traveling speed. It startles me every time! during this time, the speed gauge drop then resumes regular speed, check engine light appear but immediately turns off as does the words "park assist off" also displays then immediately goes away. These sporadic episode are becoming more frequent and could cause tragic accident. I have made several attempts to have issue dignosed but unfortunately does not generate codes, according to onstar. Dealership was unable to duplicate the issue. However they recommended replacing throttle position sensor, brake lamp switch, spark plugs and wires, master cyl and brake booster, flushing and replacing brake fluid for possible solutions but it did not fix the problem. What I have notice the issue becomes more frequent when there is studden braking(stop and go traffic) followed by increased acceleration. In addition while sitting idle in park for about 10mins with A/C on, truck idles down like it is about to cut off(engine light comes on then immediately off) but doesn't. dealership was unable to duplicate that too. Also after braking for stop light I sometimes feel several thumps as though I'm not putting enough pressure on brake peddle. No matter how much pressure I put on brakes the thumps still sporadically occur. Sometime when this happens it is followed by the first issue I meantioned when driving is resumed (hault, engine light, park assist off warning).

- Charlotte, NC, USA

Own a 2008 Suburban and had exact problem five (5) times and paid to repair (5) times. We have called GM consistently relative to problem and will not admit issue. We have learned other owners having similar issues with stabillitrak sensors. The vehicle immediately drops speed to 20 miles an hour during driving. My understanding, the vehicle receives senor reading relative to sterring and stability (potential for vehicle to spin out of control). Issue is the vehicle immediately drops speed which can cause potential for severe "rear-end" accidents. I called your hotline "without return calls"!

- Baton Rouge, LA, USA

Electronic accelerator, cuts in and out, and accelerates without warning.

- Sarasota, FL, USA

2008 Chevrolet Suburban. Consumer states unintended sudden acceleration. The consumer stated the vehicle accelerated rapidly from a standing start to enter the traffic lane ahead of oncoming traffic from the left. He depressed the accelerator pedal quickly, then let up, but the engine RPM continued to climb, as if the accelerator were fully depressed. Upon hearing the engine continue to accelerate on its own, and feeling the vehicle surge forward, the consumer applied the brake with full force, using both feet and was successful in bringing the vehicle to stop; distance traveled was about 40 feet from the point where the brakes were applied. Once stopped, the consumer put the transmission in park, where upon the engine accelerated to the rev limit. He immediately turned off the engine using the ignition switch, to avoid engine damage. After a moment, he restarted the engine, which resumed normal operation.

- Wilmette, IL, USA