Sounds like the controller is having problems. The steps work about the same as power windows in a car. Many models even use the same motor. No limit switches and such so the controller monitors how much power the motor is demanding. Once the demand gets past a preset limit the control assumes the steps are retracted or extended and shuts the motor off.
A few things to check. Make sure the ground wire from the steps to the coach frame has a good contact. Best to remove it and use a bit of sand paper to clean everything up. A poor ground will cause erratic operation. Check the power connector and make sure the pins are clean and not corroded and such. You can use spray electrical contact cleaner if needed. Lastly use a bit of dry lubricant on all the pivot points of the steps.
Be very careful working on the steps. If your fingers are in the wrong place, particularly when the steps retract, you'll probably need to talk to a very nice person wearing scrubs.