Our automatic coach step is not powered by the coach batteries ... it's powered by the main engine battery. Whenever the main engine is started, the step gets automatically retracted.
We do have a separate step switch right by the coach entry door where the step is that can be switched to keep the step out regardless of what you do with the coach entry door - we leave the switch in this position to keep the step always out when camping. Normally the coach entry door opening/closing will open and close the automatic step.
However, no matter what position the step switch is in, starting of the main chassis engine will always close the step.
Obviously, this kind of setup is only possible with a motorhome, not with a towable RV.