Traverse

My wife's 2012 traverse check engine light came on
going down the highway then moments later killed
the engine and now won't start has power to
everything but when you turn the key to crank the
motor it kills everything until you let off I like in a
small town and no local shops will touch it and it's
350 to have it towed to the closest Chevy dealer
just wondering if you have any idea was hoping it
could be an easy fix thanks in advance