At approximately 50 mph coolant loss from a cracked cylinder head sent a signal to the ecm to shut down the engine which caused the loss of power steering and control. weather conditions were snow and wind and i was following two dry tracks in the road, upon loss of power the truck drifted onto an area of road covered in snow which nearly carried me off into a ditch. on a dry day if this had occurred inertia would have taken me on to a soft shoulder so in this instance the cold weather and snow actually helped the truck from drifting too far off the road. once disabled along side the road the weather began to deteriorate to near white out conditions, thankfully another driver pulled up behind me about 50 yards back and used his flashers to warn on coming drivers. after the truck cooled a bit it re-started and i took for service. a mechanic noticed a cracked cylinder head as the culprit. i have come to learn this is a common problem with these vehicles. my wife will occasionally drive this truck and it could have been a different situation if she could not have muscled the unassisted steering to the side of the road. it is my belief that any condition that will shut down an engine under full power should be the responsibility of the manufacturer to fix. *tr