Hi,
Let's try something. On the transfer case is the shift motor. Make sure the vehicle is in 2wd and disconnect the shift motor to see if the problem stops. If there is no change, then it's likely not the electronics. If it stops, we need to work backward to see if we can determine where there is an issue. See pic below
Keep in mind, the vehicle has a 4wd control module under the dash that could be the problem. If possible, scan the can-bus to see if there are codes in that module indicating an issue.
Here is a link that shows how it's done:
.
https://www.2carpros.com/articles/can-scan-controller-area-network-easy
Let me know if that is something you have done or can do.
Take care,
Joe
See pic below.
Image (Click to make bigger)
Monday, May 15th, 2023 AT 6:56 PM