I got codes on my Duramax Diesel on my last trip and when I took it to the Chevy dealer they said my fuel overheated to 260 degrees . I have never heard of this . My truck got up to 235 on the engine ...
First get a code reader -cheap and something good to have. Once you know the code research causes on dieselplace.com. Some good suggestions about checking fuel cooler - small radiator under truck in front of driver side rear wheel. Clean it if plugged with mud. Then also possible are collapsed lines.