I have a similar Coachman 2014 Mirada 29 DSSE and I believe this is the switch to override the brake on the front slide. The brake keeps the slide from moving in or out while in transit or while parked. You may at some point in time need to "manually" extend or retract your slide for repairs etc. Just be aware that this requires power to the electric brake to use this switch. I had a mouse eat the fine wires to the brake and rendered this switch unusable until I repaired the wires. Once you disengage the brake you then have to connect a socket, long extension and ratchet or drill driver to "manually" extend or retract. Hope this helps.
