I cleared the codes. Took the electrical connection loose on transfer case (had water in it) dried it out and applied dielectric grease and so far so good. Put in 4wd drive and checked codes again. None displayed. We'll see.
Need some help from those who know better than I. I have a 2004 GMC Sierra 2500 4wd that had the infamous "Service 4wd" come up. It resets itself at engine restart and does not display all the time. The following codes are displayed: B0790 - Transfer Case Neutral Indicator Circuit B2725 - Mode Switch Circuit C0306 - Motor A/B Circuit C0327 - Encoder Circuit C0374 - General System Malfunction U1084 - Unknown U1301 - Unknown Truck drives fine with no problems. When "Service 4wd" comes on, the 4wd will not engage but turning off engine and restarting resets it. After restarting it will go in and out of 4wd. It does this about once every 4 weeks or so. I have read alot about moisture issues but wasnt sure with so many codes at the same time. Hopefully someone has seen this combination before and can provide some guidance so I dont waste time and money on symptoms and not the cause. Thanks for looking.
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