2010-2015 GMC 6.6L SCR Dosing Module2010 2015 GMC 6. 6L SCR (Selective Catalytic Reduction) Dosing Module Applications: 2010 2015 GMC Express G2500, Express G3500, Express G4500, Silverado, Savana, and Sierra. The Bosch Denoxtronic System is the leading OEM emissions solution utilizing Selective Catalytic Reduction technology. SCR technology is an exhaust gas treatment design to reduce oxides of nitrogen (NOx) emissions from diesel vehicles. The Denoxtronic system is made up of the SCR