Hey, did you get this issue solved? Someone told me it has to be the actuator on the transfer case since 4L works every time and 4A and 4H are intermittent.
Thanks a lot for this info. My ACC has been working fine after my 2" leveling kit, but I wanted to cure the "ping pong" effect with the lane assist and heard this would help out. I'm going to do this procedure today and see if that will do the trick!