The EPA recently approved rules that require heavy-duty trucks over 14,000 lb to be equipped with an onboard diagnostic system. The rule applies to trucks with a gasoline or diesel engine. Trucks under 14,000 lb already are under EPA mandate. The mandate for trucks over 14,000 lb will be phased in, beginning with one engine family per manufacturer in the 2010 to 2012 model years. The remainder will fall under the mandate in 2013. To enable third parties to service the engines, the rule requires that manufacturers make the OBD data as well as information related to other emissions-related engine components, available to them.