Kiwkee used to have a diagnostic PDF on their website - not sure if new owners still have that. Worth a look.
If you disconnect the motor swing arm from the step it will allow the step to open freely - if the problem is just binding then the motor should now operate and you can focus on lubing. If the motor doesn't operate with the steps disconnected you might want to try and connect the motor directly to 12 volt battery -- that essentially bi passes the electronic control and if the motor doesn't operate then your going to need to replace the motor.