NHTSA Preliminary Evaluation PE24002

On January 31, 2024, the Office of Defects Investigation (ODI) opened PE24002 to investigate allegations of loss of motive power in model year (MY) 2021 Ford Bronco Sport vehicles. At that time, ODI had received 31 Vehicle Owner Questionnaires (VOQs), with consumers commonly reporting a loss of engine power accompanied by complete electrical system failure which occurred either while driving, or after coming to a stop. The investigation revealed that MY 2021-2024 Ford Bronco Sport and certain MY 2022-2023 Ford Maverick vehicles are equipped with a 12V enhanced flooded battery (EFB), which may experience an abrupt failure during a drive cycle. The failure is the result of an internal corrosion issue, which is influenced by long exposure to high under-hood temperatures. If the sudden loss of 12V battery voltage is not detected by the vehicle’s battery management sensor, the vehicle can experience a loss of power event without providing any warning to the driver. Following a loss of power due to battery failure, the vehicle may be without all 12V accessories including hazard lights and typically will not be able to be restarted. In its March 2024 response to ODI’s information request, Ford provided 367 customer complaints (including field reports, lawsuits, and legal claims) and 1005 warranty claims relating to the alleged defect. When combining ODI and manufacturer failure report data, there are 1,368 unique VINs represented across MY 2021-2023 Ford Bronco Sport vehicles. One of the VOQs submitted to NHTSA reported a minor rear-end collision resulting from a loss of power event. Included within Ford’s complaints were a reported single-vehicle collision and a vehicle fire which occurred following a loss of power event at a traffic light (fire cause and origin was not determined). Additionally, across ODI and manufacturer data, there were 12 allegations of either acid leaking from the 12V battery or smoke emitting from the battery area within the engine compartment. On