— Ford 12-volt battery problems caused the opening of a federal safety investigation in January, but the investigation is closed based on two Ford recalls.
The investigation was opened after 2021 Ford Bronco Sport owners complained their vehicles lost power.
Ford Bronco Sport drivers said the electrical systems completely failed while driving or after coming to stops.
According to the National Highway Traffic Safety Administration:
"The investigation revealed that 2021-2024 Ford Bronco Sport and certain 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."
The driver will receive no warning of a sudden loss of 12V battery voltage if it is not detected by the battery management sensor.
A big consequence is hazard light failure from a loss of electrical functions when a vehicle stops moving. In addition, there will be no restarting of the vehicle.
In response to NHTSA, Ford provided 367 customer complaints, field reports and lawsuits, and 1,005 warranty claims relating to the battery problems.
There were also 12 allegations of either acid leaking from the 12V battery or smoke emitting from the battery area within the engine compartment.
In April, Ford battery problems caused a recall of 456,000 model year 2021-2024 Bronco Sport and 2022-2023 Maverick vehicles to update calibrations to the body control modules and powertrain control modules.
"Ford indicated that the update will result in improved detection of 12V battery state of charge during drive cycles and will provide notification to the driver if the battery significantly degrades while driving." — NHTSA
Ford also replaced the 12V enhanced flooded battery with an absorbed glass mat battery.
This was followed by a Ford Maverick recall of about 800 trucks for low battery charge conditions.
Safety regulators believe Ford's recall actions will take care of the low battery problems.