GM won't give us the option to disable it and keep our warranty until they put out enough money for warranty repairs. They have my buddies wifes Yukon in now for a total rebuild at 48,000 miles because the rings froze to the pistons from running in AFM mode so much. It has zero compression on cylinder #8. His own truck just went in last week for a whole new upper end since one of the AFM lifters puked. I'd hate to lose the warranty on my 2011 LTZ over putting an aftermarket tune on it. I sure wish there were a way we could disable AFM through the dealer so we could keep our warranty.