COOK and stir corn in skillet on medium-high heat 3 to 5 min. or until golden brown; cool slightly.
HEAT grill to medium-high heat. Combine corn, onions, tomatoes, cilantro and crushed pepper. Mix lime juice, mustard and sugar; stir into corn mixture.
PLACE ham steak on grill; brush with barbecue sauce. Grill 7 to 9 min. or until heated through, turning after 5 min.
SERVE ham with the corn relish.