Federal safety regulators opened an investigation into what’s going on with the all-electric 2021-22 Ford Mustang Mach-E after customer complaints about power loss have continued despite having records of repair following a recall last year.
At issue is how Ford has handled the recall and whether it implemented an effective remedy. An estimated 64,727 Mach-E vehicles are covered by the investigation, according to an Office of Defects Investigation document filed with the National Highway Traffic Safety Administration. So far, 12 reports have been put forth from consumers whose vehicles had been reportedly fixed but the fix didn’t stop the problem, said the report, dated Aug. 17.
The investigative document lists 44 early warning field reports. No accidents or injuries have been reported, according to the safety website.
Regulatory documents focusing on the power loss problem point to a software update issue.
“We are working with NHTSA to support their investigation,” Ford spokeswoman Maria Buczkowski told the Detroit Free Press on Monday.
Ford recalled 48,924 of the 2021-22 SUVs built between May 27, 2020, and May 24, 2022 but the latest document from investigators indicates nearly 20,000 more vehicles were covered by the investigation.
“This recall addressed high voltage battery main contactors that may overheat from direct current (‘DC’) fast-charging and repeated wide open pedal events,” the report says. “Overheating may lead to arcing or deformation of the electrical contact surfaces, which may result in a contactor that remains open or a contactor that welds closed. An overheated contactor that opens while driving may result in an immediate loss of motive power without re-engagement, increasing the risk of a crash.”
A “wide open pedal event” refers to rapid acceleration.
Ford said the remedy in this recall was a software update to monitor contactor temperature and reduce battery power to prevent damage to the contactor, and a software update to monitor contactor resistance to identify an overheated contactor and reduce vehicle power to prevent further damage.
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Ford said in a June 10, 2022 document supporting the recall, and consumer letters, that if the contactor opens while driving, a powertrain malfunction warning light will be illuminated and the vehicle will display “Stop Safely Now” in the cluster when the vehicle experiences an immediate loss of motive power. Should the contactors weld closed while driving, a powertrain malfunction warning light will be illuminated on the next drive cycle, along with a no start condition.
By October 2022, Ford reported fixing 36,365 Mach-E vehicles. Those vehicles are part of this investigation.
Consumer complaints continue to be reported on the NHTSA.gov site, including one from a driver in Ashburn, Virginia, who experienced loss of power when going about 50 mph on July 23. The driver said the temperature was neither too hot nor too cold and a high-voltage battery warning lit up.
The Mach-E is built at the Ford plant in Cuautitlan, Mexico, and the plant expanded this year to increase production capacity.
Meanwhile, Ford is working to remedy a recall fix related to the camera system on its 2023 Ford Explorer, too.
Contact Phoebe Wall Howard: 313-618-1034 or phoward@freepress.com. Follow her on Twitter @phoebesaid.