Heat grill to medium heat.
Thread wiener pieces onto 4 skewers alternately with pineapple and vegetables. Brush with 2 Tbsp. barbecue sauce.
Grill 8 to 10 min. or until wieners are heated through, turning and brushing occasionally with remaining barbecue sauce.
Remove ingredients from skewers. Fill buns with Singles, wiener pieces, pineapple and vegetables.