EPA Proposes Onboard Diagnostic Regs For Trucks/Buses

Posted on December 13, 2006

The U.S. Environmental Protection Agency (EPA) is proposing to require the emissions control systems of large diesel and gasoline on-highway trucks and buses to be monitored similarly to passenger cars. EPA said its proposed regulation for onboard diagnostic (OBD) systems for large trucks and buses would help ensure that emissions control systems work properly for the useful life of heavy-duty on-road vehicles.

Onboard diagnostic systems, used in passenger vehicles since the mid-1990s, monitor emissions control components, detect need for emission-related repairs, and alert the vehicle's operator of these problems. They also help inform service technicians what problem exists so that it can be repaired properly. The OBD systems for highway trucks will work the same way, EPA said.

The proposed requirements are part of EPA’s Clean Diesel Truck and Bus Program, which the agency said will result in significant reductions of nitrogen oxides, particulate matter, non-methane hydrocarbons, carbon monoxide, sulfur dioxide, and air toxics from diesel-powered vehicles.

The proposal also makes changes to certain existing OBD requirements for smaller highway diesel trucks.

More information on this action: http://www.epa.gov/obd/regtech/heavy.htm