OK, this is a weird one. 2006 Silverado 2500HD 189k only trans mods are a transgo JR shift kit a few years ago. Went hunting and up a very bumpy road for about 10 miles, very very slowly. Came back down the road again very very slowly and went to town. When I got back on the road to head back up the trans went into limp mode and I had no speedometer. I have an edge monitor so I cleared the codes and drove to town with no speedo. Bought a VSS and replaced it. Got my speedo back. All shifted fine until the trans warmed up and now I'm getting 3 codes. P0762,P0776,P0777. If I let the truck cool down I can start and drive it normally until it is warmed up then at the first stoplight or stop, back to limp mode. I've always done regular maintenance and the tranny fluid is full and good color. Anyone ever seen this?