When you keep your EV plugged in, you expect it to be ready to go when it is charged, right? Unfortunately, that is not the case for some owners whose Ford Mustang Mach-Es were built on or before February 3, 2021.
Yep—even some EVs have onboard 12-volt batteries for starting and powering accessories when the car is off, just like conventional internal-combustion vehicles do.
Such is the case for the Ford Mustang Mach-E, though the problem is exaggerated by the buggy factory software, which isn’t topping off the 12-volt properly while the SUV is plugged in and charging its larger lithium-ion battery pack.
Affected Mustang Mach-Es, according to the NHTSA service bulletin Ford initiated, the powertrain control module ‘s programming is preventing the 12-volt battery from sipping energy from the big pack while the high-voltage battery itself is sipping energy from the grid.
Before you ask, yes, it is possible to jump-start an EV’s 12-volt battery—just like in your gas-fed ride!—but since the Mach-E’s 12-volt battery is hidden within the front trunk, the process is tedious.
Given how the Mustang Mach-E is capable of receiving over-the-air updates wirelessly, in theory, Ford could quickly and painlessly fix the software problem the way Tesla is known to do.
In any event, while inconvenient, the Mach-E’s little charging problem belies the automaker’s noble push for data security.