15411 - SERVICE UPDATE. THIS BULLETIN PROVIDES A SERVICE PROCEDURE TO INSTALL FUSES AND RELAYS AS REQUIRED IN THE UNDERHOOD ELECTRICAL CENTER (UEC) ON CERTAIN 2015 MODEL YEAR CHEVROLET SILVERADO AND GMC SIERRA VEHICLES EQUIPPED WITH AN ACCESSORY-WIRING-JUNCTION-BLOCK (RPO 9L7). THESE VEHICLES MAY HAVE MISSING FUSES AND RELAYS. THE CUSTOMER MAY NOTICE THAT THE AUXILIARY SWITCHES ARE INOPERATIVE AFTER THE FUNCTION IS ADDED TO THE VEHICLE.
