Hey guys,

I have a 2004 Silverado and I have been having problems with the "Service 4WD" light. It used to come on occasionally and I'd just have to shut the truck down and start it back up and all would be fine. Well over time it became more frequent and now for the last couple of months it's been constant. When I start the truck (every single time) the lights on the 4WD selecter switch light up but then after that initial check, the lights go out and none of the buttons work. Right as that happens, the Service 4WD message pops up. It happens every single start up and happens immediately. I have taken out the switch and checked all the solder joints, and have even touched some of them up, but it didn't help at all. So I am convinced that the switch is fine, especially since it lights up when the system "checks" it on startup.

So my next best guess is that the encoder motor needs to be replaced (which is spendy) or it may just need a new encoder motor sensor, which is like $60 and from the YouTube videos and write ups i've seen, it seems easy to replace. I don't have $100 burning a hole in my pocket to take it to a dealership to have any codes read, so I am trying to troubleshoot the best I can. Does anyone have a guess as to whether the entire encoder motor needs replacing or if it's maybe just the sensor?

If you need more info, please let me know. I appreciate any insight anyone can provide. Thanks.

 

May also be the switch. Check the connections in the back. Guy at work had similar issues. Turned out the connections into the switch were loose