'01 K2500 ABS light, Dr. light flashes

[illinoisduramax]

I have a '01 K2500 4x4 with Duramax diesel and Allison transmission. Sometimes when I hit a bump the ABS light comes on and the brake red light also comes on. Sometimes they go right out and then sometimes they stay on until I stop and shut the truck off and then restart it. Then to add fuel to the fire, the transmission will feel strange and then the drive indicator light starts flashing and the truck starts coasting, so I stop, shift into neutral, then back to drive and then it runs ok for a day or so before doing it again. Hope I explained this right. Could there be a loose connection or a short somewhere? It has 85,000 miles and is out of warranty. Dealer checked with computer and found a couple of codes, but would need more time to diagnos the problem. HELP!

 

illinoisduramax

[ChevyTech007]

Need to know the codes.