Forum Discussion

isaacd's avatar
isaacd
Explorer
Feb 22, 2015

2009 GMC Sierra 3500 issue

This may be a long shot but I just developed an issue with the above Duramax. I am currently in the Seattle area and everybody is closed.
Truck has been perfect until today, has 70000 miles on it. Just traveled from CO 2 weeks ago.

Driving today and stopped at a NF pulloff, when we got back in and started engine the brake light and the ABS light was on. Then the check engine light. Shifted into gear and the indicator didn't work. Get it into drive and it will not shift out of 2nd I think{top speed 45 at 2500rpms). The automatic door unlock upon shifting into park doesn't work. The digital trans temp does not display and it shifts into reverse or drive roughly. At one point the radio backlight went out and then the door lock actuators keep clicking but not locking or unlocking.

Made it back to RV slowly and now wondering what the heck it could be.
Google says anything from ECM, BCM, TCM, and my buddy who is a Ford tech in NM says maybe ground issue.

Anybody have the same problem? Thanks for any help.
  • 6yrs old just replace em. That is about the most you get out of batteries these days. Chances are one or both are bad, or close to it. Low batts can do all kinds of weird things on these trucks.
  • I bought the truck at 36000 miles and have not changed them. I will check them, I assume disconnect both and check individually?
  • Batts are the first thing I would check too. Sounds like one has shorted internally.
    Check the voltage of them separately with DVM. If one is much lower you've found your problem.
    Could also be corroded connections if the batts check OK. Clean both tends of all the batt cables - dont assume they're fine just because they look good.
  • are your batteries original? If they are-you'll get all kinds of weird electrical issues when they start to go...