As other post said check switch by door first and also see if you have a house battery switch by the door on a panel. It may have been shut off by a foot or something hitting it.
I had the same problem on two occasions and here is what it was.
First time the sticky tape that hold the outer connector on the door came loose and wouldn't make contact with the inner connector to let the steps know the door was open or closed. Replaced the sticky tape and worked fine.
Second time was the house batteries were so weak they wouldn't provide enough juice for the step motor to run. I charged the batteries and finally had to replace them as they were 14 years old. Once I did that the step open and close quickly.
Hope this helps.
Retired Army, Disabled Veteran
Wife, me, and 2006 Coachman Cross Country 372DS makes three, Demco Kar Kaddy SS