Diesel Bombers

I've think i got my problems narrowed down to it being the PCM, but I need opinions. A few weeks ago, I hit a culvert pretty hard in my 98 12 valve auto. Since then, none of my gauges work, my odometer flashes, and my transmission doesn't shift. It feels like it is stuck in 3rd gear. If i put in 1 or 2, it's like nothing is wrong with it. All of my fuses are good, I started checking relays and found that every relay has 2 wires that are hot going to it except the transmission relay. I googled where the relay gets its power from and it comes from the 2nd clip(the white one) and the wire is dead at the PCM. My question is, is it possibly a ground to the PCM or is it just the PCM? If it makes any difference, truck stays running a second or two after turning the key off. Any help would be greatly appreciated.