Quote Originally Posted by rhs98jeep View Post
Ok, so few things I learned. The front wheel sensor is in the Hub, like the Hub and sensor are one unit, and a pricey one at that. Apparently that is how the new 3500s are setup.

I tried my buddies scanner, it was no additional help past what mine said.

So what I did: I plugged the actuator back in, cleared all codes and it immediately went back into 2wd and the Serv 4wd light went away. I put into 4wd and drove up and down our gravel driveway trying to simulate the distance I drove up our cabin road before the Serv light triggered. It didnt ever come back on, however, not sure it was a great simulation. I did try switching it back and forth from 4hi, 4lo, and 2wd, all worked well. I visually scanned all the wiring to the front wheels to see if I could spot any damage or irregularities, it all looked perfect. The truck only has 22k miles on it, so everything is clean underneath and easy to follow wires. I realize visual checking is not as good as a multi-meter, but I did not get into that.

I plan to just see if this reappears or gets put to rest. I will make sure I have the scanner with me at all times so I can reset things if it does lock me out again with the Serv light. At that point, I may consider changing the hubs/sensor units in the front at 300 bucks a pop.

Hopefully it will stay off and work right, will keep up all posted, not going down to the cabin till mid april though.

I wanted to post an update so if anyone else had this problem it may help them out.
Thanks Bob, appreciate the help!!!
Thanks for the update, pleased to hear that simply clearing the codes has resolved the issue for now.

I am still confused on the wheel speed sensor availability for the front wheels.

I was also thinking the hub assembly needed to be replaced, but then I found the ABS sensors available for a 2020, 3500 (see post #6).

If anyone has additional information on this, it would be appreciated.