I was headed out of town and stopped in the neighborhood at a stop sign. As usual, the Auto Stop/Auto Start feature turned the engine off and when I lifted my foot off the brake pedal to reengage the engine, the truck started rolling backward. The engine would not start even though all the gauges and systems were working as if the engine was on. I had the truck towed to my mechanic and after troubleshooting, they determined the engine was locked up and would need to be totally replaced. My truck has the 6.2L gas engine and have since learned that GMC is recalling later model trucks with this engine in them due to engine failure. If my engine failure had happened anywhere other than at a stop sign in a neighborhood, it could have caused a significant accident. I can’t find a new engine because of the GMC recall and the cost to replace the engine with a lower mileage, used engine is approximately $16,500.