I believe the slideout motor is warrantied for 2 years by the manufacturer. Keystone only "administers" the warranty during the first 12 months of your ownership.
So, depending on when you bought the trailer, if it was more than 2 years ago, then no, the repair isn't covered by any warranty (unless you have an extended warranty, and some of them don't even cover electrical components....
If you're handy, you can remove the slide motor, take it to an "electric motor repair facility" or to a "auto alternator/starter repair shop" and they may be able to repair/rebuild the motor.... Some of the motors are repairable, some aren't, so worth a try if you're around some town with a shop that works on motors.
2015 F250 6.7l 4x4
2014 Cougar X Lite 27RKS