Starting in 2010, heavy-duty diesel engines will begin carrying emissions-monitoring technology as part of onboard diagnostic (OBD) systems similar to those now found on passenger cars. A new rule issued by EPA phases in over a three-year period requirements that on-highway trucks over 14,000-lb.-GVW monitor emissions systems and alert the driver if malfunctions cause those systems to exceed 2010 emissions limits. The OBD systems are also required to store diagnostic information that can be accessed by repair technicians.

Last year the California Air Resources Board (CARB) issued a similar rule for trucks under its jurisdiction. While not identical, the new Federal action essentially “establishes a nationwide standard for OBD so one system can be developed that can be certified for both [rules],” says Joseph Sucheki, spokesperson for the Engine Manufacturers Assn.

The new EPA rule specifically calls for each engine maker to install OBD systems on “one family” in their heavy-duty model lineup starting in 2010. Providing a phase-in period to help manufacturers perfect the systems, OBD will not be required on all HD diesels until 2013.

“Our members are confident that everything in the [EPA] rule is feasible and can be accomplished with existing technology,” Sucheki told Fleet Owner.

Although OBD will require some new sensors, it will also take advantage of sensors already in place, according to Steve Berry, director of government relations for Volvo Powertrain North America. The 13L Mack MP8 and Volvo D13 diesels will get the initial OBD system in 2010, but “it's too soon to say how much” emissions technology will add to vehicle costs, Berry told Fleet Owner.

The new rule also tightened emissions monitoring thresholds for diesels in trucks under 14,000 lbs. GVW, which have been required to employ OBD since the early 2000s. In particular, NOx emissions limits starting in 2010 are so low that engines meeting them will not be capable of even producing enough NOx to exceed the current allowable OBD thresholds.