15217 - SERVICE UPDATE. THIS BULLETIN PROVIDES A SERVICE PROCEDURE TO INSPECT THE ROUTING OF THE TRANSMISSION CONTROL MODULE (TCM) BRANCH OF THE ENGINE-WIRING HARNESS ON CERTAIN 2015 CHEVROLET SILVERADO AND GMC SIERRA HD VEHICLES THAT ARE EQUIPPED WITH DUAL GENERATORS (KHB). DEALERS ARE TO ENSURE THAT THE HARNESS IS ROUTED PROPERLY AND SECURED WITH A FIR-TREE CLIP. ON THESE VEHICLES, THE TCM BRANCH OF THE ENGINE-WIRING HARNESS MAY HAVE BEEN MISROUTED AND NOT SECURED WITH AN EXISTING FIR-TREE CLIP ON THE AUXILIARY-POSITIVE BATTERY CABLE, POTENTIALLY ALLOWING THE HARNESS TO COME IN CONTACT WITH EITHER THE AUXILIARY-GENERATOR PULLEY OR BELT.
