Car Accelerates On Its Own problems of the 2015 GMC Acadia

On 15 plus occasions, while the vehicle is stationary, in the parking gear and running, the front end will start to vibrate mildly, increase in intensity and then the traction loss light illuminates, a blinking engine light illuminates, "service stabilitrak" and "service traction control" messages appear. Then traction contol off appears, followed by an audible loud click and vibration ceases, messages disappear and lights turn off. Once while vehicle in drive and being operated on a roadway, I pulled right at an intersection to have this same sequence happen during driving, resulting in an almost complete loss of power and acceleration and a near accident. The sequence was identical and once the errors cleared the vehicle accelerated rapidly and forcefully. I have documented multiple occasions on video while stationary over a multi month period and have furnished those documents to my local GMC dealership which has failed to repair this issue and today returned my vehicle to me with an apology for not being able to remedy the problem. They claim that the vehicle must exhibit this behavior in their presence to warrant a fix. The vehicle is under an extended warranty that clearly covers these problems. I would be happy to email the videos, but they are not in the supported format and likely larger than 5mb.

The contact owns a 2015 GMC Acadia. While driving various speeds, the vehicle experienced unintended acceleration and the contact had to exert excessive pressure to the brake pedal. The contact then heard an abnormal noise coming from the front of the vehicle. The contact stated that the vehicle independently disengaged and slowed down. There were no warning indicators illuminated. The vehicle was not diagnosed or repaired. The manufacturer was notified and made arrangements to have the vehicle towed to a dealer. The failure mileage was 35,021.