Started up my 2024 Denali Ultimate today and put the shifter in Drive and could immediately hear the driver's side power running board cycling back and forth from "out" position to "rear bed step" position. After repeating that back and forth movement several times, the running board is now stuck in the out position and won't move at all to retract, or move to the bed step position with the switch at the rear of the running board. Using the on-screen menu, can command the passenger side to move to the stow, deployed, or bed positions without issue so at least the right side is working.
Beyond the normal "unplug it" by disconnecting the battery to reset the computers, any other troubleshooting to figure it out before calling the dealer on Monday? Looked in the Owner's Manual and don't anything that is obvious labelled fuse. And if it was a fuse, would think both sides would stop working.