1991 plymouth voyager 355 code

I Have A 1991 Plymouth Voyager with A 3.0 engine That keeps on Coming Up With 355 Code... Is That Code Something particular Or is it A Number of things... I Had in In To A Mechanic And He Couldnt Seem To Find what The problem Was... One thing I Did Notice Was in Winter the Van Wouldnt Even Start While plugged in... Once it Warmed Up The Van then Would Start. Everything on The Vehicle Checked Out Fine And Baffled A Few Mechanics to What The problem is... The 355 Code is Still There And i even Tried Disconnecting the Battery For An Hour to see if Computer Would reset..Well the Code is Still there Any Sense To Whayt the problem Could Be..