hello everyone i need some ideas on this Cat F30 serial # 5DB1612

its an intermittent problem, when you are traveling and move the dir lever from fwd to N the truck will just die, you can recycle the key switch and the unit takes right off.
also if you are traveling in either direction and raise your foot off the accel pedal quickly the unit dies also. but if you raise your foot slowly it will not fault out.

any ideas would be appreciated

oh yea it shows code F when it fails