GMC Troubleshooting Questions? Ask a Mechanic for Answers
Welcome, I'm Chris (aka Moose) I prefer to work when others don't, I am here around lunch and after dinner till after midnight.working after noon till just after midnight.
What tools do you have at your disposal for diagnosing? This looks to be a faulty DEF tank level sensor to blame here. If you are stranded a reset may work and get you down the road a little farther to a repair facility. To do a reset you disconnect the auxiliary batter then disconnect the primary battery. On the primary you hold the cables together for one minute then reconnect both batteries 30 minutes later.
This is my 1st answer, but does not have to be my only answer. You the website and myself expect you to have a great experience with my help. Please let me know if you are pleased by selecting a star rating above or by replying and saying your pleased. Not rating or rating 1-2 stars does not benefit you nor me in any way. Follow up and reply as often and when needed, there is no extra charge to do so.
Remove the battery cables and hold them together so the negative and positive are touching to discharge all electronics.
Hello again Chris here,