Thought I would share my experience in case anyone else has this problem. I was having an issue with the error code 9 as well on both the main slide control unit and the controller for the bed over the cab on my 2017 34j. I spent quite some time trying to figure it out through forums and videos to no avail. I tried to schedule a mobile repair to come out as my slide was extended and couldn’t get it to come in. After no one being available I decided to figure it out on my own thinking that it has to be a ground wire somewhere. So I took off the bed in the back and got into the wiring. For those that don’t know, all the main wiring, transfer box, etc. is under the bed and you access it by removing the screws and removing the panel that is on the left, above the breaker panel. Anyways, it turns out the main ground post that is bolted into the side of the bed, look for a bunch of white wires going into the post, was loose. All I had to do was tighten the nut and that solved the problem. Happy RV’ing.