GMC Troubleshooting Questions? Ask a Mechanic for Answers
Hi, I’m Ron and I can help you.I have been in the auto repair business with my own shops since 1975 and also teachautomotive repair. I am confident we can resolve your problem together. Pleaseunderstand that I don't know your skill level. In most cases when you have a problemwith the way the vehicle performs, specialized tooling is required to acquire computerdata/information or engine testing results. We didn’t build these complicated vehicles; wejust diagnose and fix them. Also understand that I can't see, smell, hear, or touch thevehicle either, so it may take a few replies to get to satisfactory results. I am also going todirect you with the fastest, easiest and most common things to check first. Please bepatient and permit me to do what I do best.I also try to give all of the information you may need, expecting a “positive rating” inreturn. I will also continue assisting you after you have rated me, if necessary. If thereis any reason I cannot get a positive rating, please let me know why “in advance”, so Ican go another direction for you. I am sorry you’re having this problem; I’ll help youthrough it.It sounds like it's in limp mode and they need to find out why by use of the scan tool.It doesn't sound like they did much for you at the dealer, so let's try this first. See attachment,we need to relearn the computer first, and this can actually fix it too if we're lucky.