Certain 2010-2016 model year Chevrolet Express, GMC Savana, 2011-2013 model year Chevrolet
Silverado HD, 2015-2016 model year Chevrolet Silverado HD, 2011-2012 model year GMC Sierra HD, 2015
model year GMC Sierra HD vehicles equipped with Duramax diesel engine (RPO LGH or LML) and
Ambulance Upfitter or Fire Truck Upfitter (RPO YF2 or ANM), may have a condition in which the
emission control system as designed will limit speed under certain conditions. The EPA has approved
General Motors request to remove the emission control system speed limitations on these emergency
vehicles where applicable.