I have a 2011 5.0 88,000 well maintained miles. Every time you start to accelerate (at different times) it will make a god awful grinding noise from underneath and the engine shuts down and errors out. Ignition just barley clicks when turned, acts like a battery issue, but all else is fine. Finally, if you pull relay R2 in the engine compartment and reset, the engine will start with no noise what so ever? Then, try driving and does the same thing. Don't know what it could be? Sounds very mechanical but why no issue when the engine/truck has finally restarted. Can't be good on whatever is grinding?