TCM not communicating/functioning

[WOTLeadFoot]

I am getting an intermittent transmission problem. I believe, and it has been suggested by the shop that I use, that the problem is a short somewhere. This truck is my first diesel and I've only had it a few months so I'm just starting to try and figure this out. What I see is a group of symptoms: I am loosing gear indication in the cluster as well as speed and transmission temp. At the same time I am getting the 'break' 'abs' and "service break system" information. These things all happen together but not always completely in sync, sometimes I have speed with no gear indication. The breaks operate fine and the only actual problem that occurs is that the transmission stays in one drive gear when the problem arises. When this first started my OBD/lighter fuse was blown. When my codes were read there several transmission codes including a loss of communication with TCM code. While the problem is happening diagnostics cannot communicate with the transmission. I don't know if TCM can fail intermittently or not but I believe this combination of symptoms may point to the location of a short. I REAAAALY need my truck and my shop cant get me in until the 5th of DEC!! I don't trust non-specialists with this truck. Any ideas or advice would be appreciated.

[GMC D-Max]

Start with the simplest and most basic troubleshooting: Check all plugs and connections. Look for loose plugs, corroded pins and/or moisture, and make sure no pins in the plugs are partially pushed out of the connectors.

[WOTLeadFoot]

Thank you for the suggestion. What I was looking for is a single location that could produce all of those symptoms since they are all happening together. I have located the area of the short, it is the in cab fuse box. I will post exactly what it is when I get it completely figured out. For now, I can get the connection back by moving around in the fuse area.

[More Power]

There's a major grounding point in the area near the in-cab fuse center. Several black wires with crimped-on eyes are supposed to be bolted together onto a cab stud. I'd look at that grounding connection, and make sure the nut is tight.

Jim

[Kennedy]

What year is the truck and what is the history? Bought new, bought used, wrecked, salvage, reposessed, flood, unknown, etc?