TSB: Ford Mustang Mach E Whine Noise

Some 2021-2022 Ford Mustang Mach-E (non GT) vehicles equipped with all wheel drive may exhibit a whine noise from the front drive unit at steady speeds of 30-40 mph, without any DTCs present. This may be due to software parameters. 

1. Connect a battery charger to the 12-volt battery. To prevent the battery saver mode from activating, make sure that the charger’s negative cable is connected to chassis or engine ground, not to the 12V battery negative terminal. Do not have the vehicle plugged into the high voltage battery charger.
2. Reprogram the PCM using the latest software level of the Ford diagnosis and repair system (FDRS) scan tool.
3. Check availability of software updates as required on the secondary on-board diagnostic control module (SOBDM), battery energy control module (BECM), secondary on-board diagnostic control module B (SOBDMB), secondary on-board diagnostic control module C (SOBDMC) and the ABS module. Only update one module at a time.
   Note that a small amount of whine noise is considered normal.