735i not shifting in foward gears

HELP... Ive have correct amount of fluid... and She will "think " she is in 1,2,3,D.... and she will go in reverse and will go foward... but ONLY in what i believe is 3rd.... aka around 3500rpms at 65mph.... what has happened with the trannie
??????
One day she was fine...well alittle rough... no one foward gear????:banghead:
thanks
shes an 88

Is she throwing any codes? A bad MAF will put her in limp mode and she will act as though she is trying to pull a boat anchor.