GM 6.2L Engine shifted itself into neutral and shut down while my wife was alone driving 65mph on [XXX] in Tucson Arizona. No error messages or check engine signal, Vehicle Information Center advised pull over and push Start Button. Vehicle would not initially restart but did start within 5 minutes and my wife was able to limp along the 1/4 mile to the next off ramp to get off the highway. Local GMC Dealer confirmed the seized motor and immediately ordered a new GM motor. Vehicle is 18 mo’s old with 26,500 miles and is sitting at the dealer. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)