The antenna, integrated into the rear window glass, must be replaced by a professional if faulty. For sedans, the antenna module is inside the right C-pillar. Remove the C-pillar trim, disconnect the two module connectors and the coaxial cable, then remove the module. Reinstall in reverse order. For wagons, the module is inside the liftgate. Remove the trim panel, disconnect the two module connectors and the coaxial cable, then remove the module. Reinstall in reverse order.