WASHINGTON — The nation's top auto safety regulator has upgraded its investigation of high-pressure fuel pump failures in certain heavy-duty Ram diesel trucks.
According to a document made public Tuesday, NHTSA's Office of Defects Investigation is expanding its safety probe to include the Tier 1 supplier Robert Bosch, which makes the high-pressure fuel pumps. The expanded probe also includes any automakers who installed the part and are experiencing similar failures.
In October 2021, NHTSA launched its investigation of high-pressure fuel pump failures in 2019-20 Ram 2500, 3500, 4500 and 5500 heavy-duty trucks equipped with 6.7-liter Cummins turbodiesel engines after reports alleging incidents of stalling or loss of power. The upgraded probe also covers 2014-22 Ram 1500 trucks.