General Motors released Emission Recall 17337 and Service Update 17419 on November 1, 2017. After their release, a change occurred in Tis2Web that affects the involved 2018 model year Chevrolet Silverado HD and GMC Sierra HD vehicles. This change prevents programming of the engine control module (ECM) and transmission control module (TCM) separately. Tis2Web now requires the ECM and TCM in these full-size trucks to be programmed sequentially. Consequently, dealers are confused and asking for guidance relative to labor code submission requirements. Again, the Tis2Web change only affects the involved 2018 model year Chevrolet Silverado HD and GMC Sierra HD vehicles
