C1340 Code

Hello, I have a ‘07 CM 4WD that has been giving me some issues as of recent. The first time I noticed was when I was in reverse and it slammed stop with a giant clunk noise. I was able to drive it to a friends shop and did some looking around to that noise but couldn’t find anything. I put a reader on it and got the C1340 (Center Diff Lock Circuit) code. It will still move in reverse but I intermittently get the clanging noise while doing so. I have no flashing 4HI/LO and VSC lights but it sounds as if it is still stuck in 4WD somehow. Could it be transfer case related or something else? Thanks for the help.

 

I just took my tundra away from my Mechanic. He had it for 1 year and 3 months. And made a mess of my truck letting it sit for So long. One of my issues was a C1340 and C1241. Trying looking at the rear Abs wire and rear speed sensors.