FORD F-250 SD (2012)

Investigation Summary

20160315 15V175000 Vehicle Commanded Engine Shutdown The Office of Defects Investigation (ODI) opened this RQ to investigate allegations that the scope and remedy of safety recall 13V-535 were inadequate. Recall 13V-535 was limited to a relatively small population of Ambulance Package vehicles and ODI received complaints of pickup trucks and Fire Engine Prep Package vehicles being affected by the same defect. Ford manufactured approximately 555,985 subject vehicles between February 22, 2010 and January 30, 2015 that may be affected by defective EGT sensors and Powertrain Control Module (PCM) software calibration. The subject vehicles are equipped with four (4) EGT sensors to monitor engine operating conditions. An EGT sensor fault may produce false exhaust over-temperature signals. If these signals are produced, the Powertrain Control Module (PCM) implements a Failure Management Effects Mode (FMEM) and the driver receives a Stop Safely Now (SSN) system warning on the instrument cluster message center. The FMEM triggers a 70% reduction in available engine power over a period of no more than 45 seconds, during which it may not be possible to accelerate or maintain vehicle speed. The PCM then commands the engine to shut down when vehicle speed reaches approximately 1 mph. There is no immediate restart capability. Depending on the PCM software calibration, ignition key position and ambient temperature conditions, the engine may not restart until the end of a 10-60 minute cool down period.Ford and its component supplier(s) made numerous changes to the PCM software calibration and the design, material and manufacture of the EGT sensors over the period of subject vehicle production. This continuous product improvement affected vehicle performance regarding the alleged defect. Ford acknowledges the defect condition in the subject vehicles but argues that an unreasonable risk to motor vehicle safety is limited to Ambulance Package and Fire Engine Prep Package vehicles where