ya it could be APP but 99% of the time it will set of a code

but here some info on it

you made have blow up some to read

I have the same problem with my 94 chevy 2500 6.5 td. Just started after the freeze we had here in January. Everything was good till it froze, now, when I turn key on the gauges wig out doing a full sweep several times, and almost all the time it trys to run away with itself, redlines itself but never shuts off. Then after a couple of good redlines, it wont rev over 2k-4k on tach. Truck is really pissing me off as I have a new trans, new injector pump, lift pump, pmd (remote mount), new computer, wiring has been gone through by me, new optical sensor (updated number). I am at a loss already with this thing.