15115 - SERVICE UPDATE. THIS BULLETIN PROVIDES A SERVICE PROCEDURE TO REPROGRAM AND UPDATE THE GLOW-PLUG CONTROL MODULE WITH NEW SOFTWARE ON CERTAIN 2015 MODEL YEAR CHEVROLET SILVERADO HD CREW, HD CREW LTZ, HD REGULAR, HD EXT, HD EXT LTZ VEHICLES EQUIPPED WITH A DURAMAX DIESEL ENGINE (RPO LML) AND CERTAIN 2015 MODEL YEAR GMC SIERRA HD CREW, HD CREW DENALI, HD REGULAR, HD EXT VEHICLES EQUIPPED WITH A DURAMAX DIESEL ENGINE (RPO LML). THE SOFTWARE UPDATE LIMITS THE INTAKE-AIR HEATER INPUT VOLTAGE TO 13.5V. WHEN THE SYSTEM VOLTAGE EXCEEDS 13.5V, THE HEATERÂ’S FIELD-EFFECT TRANSISTOR CAN GENERATE EXCESSIVE HEAT. THIS HEAT CAN CAUSE A SHORT CIRCUIT IN THE TRANSISTOR AND, IN RARE CASES, A FIRE IN THE VEHICLEÂ’S ENGINE COMPARTMENT.
