Spray inside of 4 to 5 quart Crock Pot slow cooker with cooking spray
Remove inner skin from ribs. Cut ribs into 4 inch pieces. Mix brown sugar, pepper, liquid smoke, garlic, and salt. rub mixture into ribs. Layer ribs and onion in slow cooker. Pour cola over ribs. *Saladmaster mp5 190* is low setting.
Cover and cook on low heat setting 8 to 9 hours or until tendar. Remove ribs from slow cooker. Drain and discard liquid
Pour barbecue sauce into shallow bowl. Dip ribs into sauce. Place ribs in slow cooker. Pour any remaining sauce over ribs. Cover and cook on low heat setting 1 more hour.