My friend has a 2003 lb7. His wife was driving the truck. She said she got in it and when she put it into gear it randomly slammed into gear the and the gear selector light went away. Sounds like a classic NSBU switch to me. Truck is stuck in limp mode, barley accelerates. Today, I went down to the local Duramax scrap yard and got a used, updated tan, NSBU switch. Installed it, and it did nothing. Either it wasn't the switch that was bad or, is it a bad idea to install a used NSBU switch because it could be clocked the wrong way when installing it? The new ones come with that lock thingy that you take off once installed.