U1301 code on lbz
Im new to the diesel world and recently purchased a 2007 gmc 2500. The truck has an exhaust, egr delete with blocker plate, and an efi live 5 tuner. The guy I bought it from says the check engine light has come on and off for a few years now, but everyone told him it’s fine and to drive it how it is. I scanned the truck and got the u1301 code. From what I’ve read online this controls all the accessories, lights, radio, gauges, etc. Everything works fine and the truck runs great. Has new batteries, newer alternator, glow plugs were recently replaced. He has a random ground wire under the hood that someone told him to do because of electrical issues in the lbz, but idk if that could be the culprit. Just not sure what could be causing this. Thanks!