prtysurinowhtimdoing

Hi. Another service 4wd post (as I've read many). Got the message on my 2010 Sierra with auto 4wd and the dial type switch in the dash. When I first got it, it was very cold and after getting instruction from phone googling, drove to hotel and shut off engine and waited. After a few mins, started truck and was fine. This was a year ago and since then this scenario has repeated itself many times no longer allowing me to "reset" the isssue but became an intermittent come and go when it felt problem - working and then not working for long periods of time and vise versa. Around Xmas I got a week of 4wd. I took it to the dealer and got scan (don't know codes). And allowed them to troubleshoot with there flowchart and whatnot. Couldn't find culprit and said program kept directing them to actuator but there was no fault there. Took it home. Looked for loose dirty ground wires. Truck doesn't have one for 4wd. I replaced the t case actuator, the t case position sensor switch (newer models have actuator at rear of case and position sensor is separate) and the dash dial switch. Still no fix bu this week I took out the front diff actuator (motorized probe injector thing). It was extended. I also jacked up font of truck and could not turn the front wheels. Trying anything here so I started unplugging and wiggling an plugging back in wires. WHEN I UNPLUGGED THE UPPER WIRING HARNESS FROM THE MODULE in the dash (ign on so I could hear stuff) the FRONT DIFF ACTUATOR RETRACTED. Plugged back in and it PROTRUDED. Um, kinda backwards, right. So that means my front diff is always engaged? Or could it be the module screwing up? They did reflash it at shop when I took it in, but that was before replacing all those parts. However service message never goes away, I never hear anything from the t case and dash switch always shows Auto 4wd selected. I could replace the front actuator but is it possible that the module (even tho it checked out fine at shop) is messed up or can the act. somehow got reversed (doubting that)? Or could it just (just?) be wiring harness or connector that's making front act. do this? I know, a lot, right? But you gotta know that I've been working and researching this for a long time. And based on the posts I've read, tried a lot of things. I have yet to see a thread with my problem. Thanks for your help.

kevinkpk

Well, since your not out anything, try reversing the polarity at the actuator. I've seen crazy stuff with Chevy pickups especially with electric locking tailgates

prtysurinowhtimdoing

Thanks Kevin. I thought about that and may do just that