Replaced motor, slider working again!
We’d been able to control it using the override for code 8 (five pushes and a hold on the controller). This error is for a hall sensor error.
Started by testing polarity on the wiring harness, which was fine. That meant that either the motor or controller was bad. Since motor cost less, we started there. (Could have been just a hall sensor, but decided to replace entire motor, not just try the sensors.)
Purchased Lippert 236575 300:1. Not sure who really made it due to plastic covering on the motor. The original one was by Shayang, No. 13398-C2 IG-42-10mm.
On outside of slide, removed the #2 square head screw. Inside, removed the old motor. New motor had black plastic coating making it too tight to slide into the space where the motor goes, so we cut a little away.
The orientation of the shaft had to be correct to slide in properly. We decided to disconnect the good motor at the controller and use the slide in/out button to correct the orientation; this worked on the second pulse. Other option was to hook up to 12 volt on red/black.
Hooked back up the good motor on the controller, put screw back in outside, waited for the code to clear.
Space was tight to this was a little tricky, but replacing the was an easy job.
Slide it back to working!