3 door locks and cruise work then do not work

My 2002 Silverado 2500HD diesel would while doing 50-70 mph, click my door locks several times, then die. If I was quick enough, and I put the car in neutral, I could restart while still doing 50+, with the key, it would run fine for a day, a week, a month, until it decided to do it again. Of course, no trouble code. I also had an "unrelated" fuel injection problem that required me to replace the fuel computer. Why? A fault that caused that the dealer computer could not communicate with the truck computer. After replacing the brain box, problem went away, for over 100,000 miles. What was happening? Don't know, but obviously something in the computer was going haywire and causing the problem. Hope this helps.