“A small number” of early Ford Mustang Mach-E electric vehicles have experienced a software glitch causing their batteries to fail and make the vehicles, at least temporarily, inoperable.
The automaker reached out to its dealers to reprogram onboard control modules to prevent the problem in the existing inventory. The failures cause the electronic control system managing the vehicle to fall into a ”deep sleep” state that requires some effort to resolve.
Like most battery-electric vehicles, the Mach-E uses both a large, high-voltage lithium-ion battery pack as well as a 12-volt vehicle battery. The problem appears to be caused when the conventional lead-acid battery unexpectedly drains while the bigger pack is charging.
Software glitch gets the blame
Ford blamed a software glitch for the problem which prevents the 12-volt pack from being able to sip power from the lithium-ion pack that powers the Mach-E’s motors.
Ford was an earlier pioneer of electrification, but the Mustang Mach-E is its first long-range battery-electric vehicle. The BEV is offered in a variety of configurations that include a standard-range 68 kilowatt-hour battery and an extended-range 88 kWh pack. The problem impacts vehicles with either lithium pack.
The automaker has a lot riding on the Mach-E — which has won numerous awards, among other honors being named North American Utility Vehicle of the Year. Ford has struggled with early launch problems with a number of recent products, including the popular Explorer SUV.
Aiming to catch potential problems before they get out on public roads, Ford advised 4,500 early customers that is was delaying delivery “due to quality checks.” For some, that was expected to push back deliveries as much as eight weeks. The automaker confirmed it would provide compensation in various forms, including additional free charging and even as much as $1,000 towards loan payments.
Ford’s decision to run the added checks appears to have been well advised. The electric SUV faced its first recall last month when 1,258 were found to have subframe bolts that may not have been tightened properly.
Now, it is racing to address the battery glitch which appears to impact “a small number” of vehicles produced before the end of last year. “Less than 2% of the vehicles produced” at this point were impacted, said spokesman Said Deep, adding that it involved “early models shipped around December.”
The problem occurs when a software glitch lets the 12-volt battery pack drain, even while the big lithium-ion pack is charging. Once that happens, it means neither Mach-E’s electrically operated doors nor hood can be opened. Ironically, that makes it difficult to recharge the 12-volt battery.
A complicated process
Owners must first pop open a panel on the front bumper and then attach a charger to two leads directly connected to the 12-volt battery to open the hood. Then, they have to access a separate panel under the hood to reach the small battery and recharge it. Once that is completed, Ford said, the pack will come out of deep sleep and the vehicle will resume operating.
The problem has been widely discussed on Mach-E owner forums, some referring to impacted vehicles as “electric bricks.” The term “bricking” refers to electric vehicles — as well as smartphones and other consumer devices — whose batteries completely fail and must be replaced. That is “not at all” the situation with the Mach-E, said spokesman Deep. The lithium-ion packs can be revived once the lead-acid batteries are recharged.
Ford not only automaker with battery problems
Bricking has been a problem in the nascent battery-electric vehicle segment. Tesla owners experienced the problem with early versions of products like the Model S sedan, though the automaker insists it resolved the matter with new batteries and software.
Ford provided revised software to dealers equipped to work on the Mustang Mach-E and said the update process is brief. In the future, the automaker plans to make such updates available directly by using smartphone-style over-the-air updates. Ford did not explain why it is not using that route now, a move that would help owners avoid a trip to the dealer service shop.
Despite early problems, the Mach-E has begun gaining ground in the U.S. EV market, something measured by the 12 percentage-point decline in market share for Tesla since the beginning of the year. Even with other new entries from manufacturers like Volkswagen, Volvo and others, Morgan Stanley analyst Adam Jonas said the Mach-E was responsible for “nearly 100% of the (Tesla) share loss.”