Problems · by component

2021 Ford Mustang Mach-E fuel/propulsion system problems

49 owner complaints to NHTSA about the 2021 Ford Mustang Mach-E cite fuel/propulsion system, 14% of all 353 complaints for this model year.

Complaints
49
14% of all complaints
Crashes
1
Reported by owners
Fires
0
Reported by owners
Injuries
0
Reported by owners
01 —Owner reports

What owners say about the fuel/propulsion system

Verbatim from NHTSA complaints, newest first
“While accelerating on a highway on-ramp, the vehicle displayed Powertrain Malfunction/Reduced Power, a High-Voltage Battery Warning. Power was reduced while merging into traffic. The same warnings appeared at about 90,000 miles and cleared on their own. This is a Standard Range RWD Mach-E, which was excluded from the high-voltage battery junction box recall. The vehicle was towed to AutoNation Ford Katy and diagnosed with HVBJB failure. Loss of propulsion at highway speeds is a safety hazard. I am requesting that NHTSA investigate whether Standard Range vehicles should be included in the recall.”
Owner complaint to NHTSAFiled Sep 28, 2026Power train, Electrical system, Fuel/propulsion systemODI 11767349
“My 2021 Mustang MachE experienced a failure of the relay which connects its high-voltage battery to the rest of the car. The car is an EV, and the result of this is that the drive-motor had no power, and the car would not move. I would like to ask, please, that all model years with this known-issue (HVBJB - high voltage battery junction box) be recalled.”
Owner complaint to NHTSAFiled Sep 28, 2026Electrical system, Fuel/propulsion systemODI 11767362
“The HVBJB ($3500 + Tax) went on my car. It is out of battery system warranty by 25,000 miles (ended at 100,000 miles, I have 125,000 miles). I called Ford Corporate and they said they "have no current programs" to give me any good will discount on the repair. This is a big, known issue with Mustang Mach-e's There was a recall for this HVBJB part / system on many of the 2021 models, but somehow mine wasn't included in the recall. I cannot afford this repair, and I was hoping the NHTSA can get involved to get me some financial relief from Ford. There was also a safety issue as this morning when this all happened, the car forced me to stop at an intersection and would not move or restart. The police had to push me through the intersection. It's currently at Chapman Ford in Egg Harbour Townshop, NJ.”
Owner complaint to NHTSAFiled Aug 6, 2026Electrical system, Engine, Fuel/propulsion systemODI 11755300
“After recall-related software updates were performed on my 2021 Ford Mustang Mach-E, the vehicle began experiencing repeated electrical and climate control failures. The heating and defrost system stopped working, leaving the vehicle without heat and causing the windows to fog, which reduces visibility in cold weather and creates unsafe driving conditions. The vehicle has been taken to multiple authorized Ford dealerships for inspection and repair; however, the problem returned immediately after the repair. The issue was reproduced and confirmed by a second dealer. A required part is currently on back order until the end of Feburary, leaving the vehicle unrepaired for an extended period. In addition, the vehicle experienced 12-volt battery failure and slow charging after the last recall update. These issues were not present prior to the recall. There were no warning lights before the failures occurred. During severe winter weather conditions in Pennsylvania, the lack of heat and defrost made it extremely difficult and unsafe to operate the vehicle. Because of reduced visibility and freezing interior temperatures, the vehicle could not be safely driven and, due…”
Owner complaint to NHTSAFiled Feb 7, 2026Electrical system, Fuel/propulsion system, Visibility/wiperODI 11716499
“Car stalled once while going to a military appt but started up 3 mins later. Car then made a noise then stalled out of nowhere on the highway at a slow speed in heavy traffic causing anxiety. vehicle then had me stranded waiting for a tow to find out it’s the HVJB .”
Owner complaint to NHTSAFiled Oct 15, 2025Electrical system, Service brakes, Fuel/propulsion systemODI 11693497
“It has several error messages including "Stop safely now". This seems to be the same issue as recall 23S56 (TSB 22-2178). The vehicle is not drivable as it will not start or go into gear. Seems to be known issue with the HVBJB.”
Owner complaint to NHTSAFiled Dec 26, 2024Power train, Electrical system, Fuel/propulsion systemODI 11632397

Showing 6 of 49 reports. Read every report on NHTSA.gov.

Data from NHTSA Complaints API (owner reports, unverified) · synced Nov 6, 2026NHTSA vehicle page

Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.