2021 Ford Mustang Mach-E · symptom sheet
Hybrid or EV system warning, loss of power
- 55owner reports
- 35,443median miles
- $3,000median quote
- 0involved a crash
Newest report Sep 28, 2026 · checked Oct 2, 2026
192 of the 347 complaints on this car are about the electrical system. 55 of those describe hybrid system.
Tick what matches of 55 reports
Hybrid system on other Mustang Mach-E years
Report counts are for each model year on its own, so a newer car has had less time to collect them. Model years with too few reports of it for a sheet: 2023.
What this problem usually is
These reports come from hybrid, plug-in and electric vehicle owners whose car put up a system warning and lost power, sometimes dropping into a reduced-power mode on the road. Others describe a car that won't charge, a high-voltage battery or inverter replacement, or a problem that turned out to be the ordinary 12-volt battery all along.
What got replaced
Owners who name the part that was replaced mention the traction battery (32 reports), the charger or port (12 reports), the 12V battery (4 reports) and the drive unit (4 reports).
Recalls and investigations
5 recalls on the electrical system cover the 2021 model year. A recall on the same system isn't always the same failure, so read the defect text.
The rear differential pinion shaft may fracture.
In the event of a low battery charge, the electronic door latches may remain locked once the driver or front passenger exits and shuts the door, possibly trapping someone who is unable to use the inside door release handles, such as a child in the back seat.
The high voltage battery main contactors may overheat.
The high voltage battery main contactors may overheat.
The high voltage battery main contactors may overheat.
All 13 recalls on the 2021 Ford Mustang Mach-E, with the owner complaints on each recalled system
NHTSA investigations into the electrical system on the Mustang Mach-E
Collisions involving ford bluecruise. Open.
Collisions involving ford bluecruise. Closed jan 17, 2025.
High voltage battery contactor failure. Closed dec 6, 2023, led to recall 23V-687.
Pedestrian alert sounds. Closed aug 7, 2023, led to recall 22V-063.
What owners paid
5 of the 55 reports quote a price. Each dot is one quote. The middle half runs $250 to $3,000.
When it happens
The middle half of failures fell between 12,000 and 100,000 miles, from the 11 reports that gave a mileage.
Is this a known problem?
The manufacturer has sent NHTSA 26 service bulletins or notices for the 2021 Ford Mustang Mach-E that deal with this problem. Newest first.
Federal rules make a manufacturer send NHTSA a copy of any notice about a defect that goes to more than one dealer or owner. Most of these are service bulletins, the repair instructions manufacturers send to dealers. NHTSA generally leaves safety recall bulletins out of this file, and recalls are listed separately.
Some 2021-2023 Mustang Mach-E vehicles built on or before 25-Jun-2023, 2022-2025 E-Transit and 2022-2023 F-150 Lightning vehicles may experience a high voltage battery stop charging condition when using a direct current (DC) fast charger level 3 with ...
Some of the vehicles listed in the Model statement above may exhibit a condition where the high voltage battery charges slowly or does not charge while using a level 1 or level 2 electric vehicle supply equipment (EVSE) after an over the air (OTA) update.
2021-2023 Mustang Mach-E and 2023 e-Transit vehicles may exhibit a condition where the high voltage battery stops charging when connected to level 1 or level 2 chargers with an illuminated malfunction indicator lamp (MIL) and diagnostic trouble code (DTC) ...
Some 2021-2023 Mustang Mach-E vehicles built on or before 24-Jun-2023 may exhibit a condition where the high voltage battery slow charging or does not charge while using a level 1 or level 2 electric vehicle supply equipment (EVSE) after an over the air (OTA) ...
22 more on the 2021 Ford Mustang Mach-E page.
What owners wrote
“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.”
Filed Sep 28, 2026
“I have had the HVBJB replaced twice. I have had 2 high voltage warnings and power train malfunction. It in the shop again for the same problem. Supposedly getting fixed for the same problem.”
Filed Feb 24, 2025
“My 2021 Mustang Mach-E GT Performance is exhibiting a Powertrain Failure and Stop Safely Now message in the instrument panel cluster (IPC). It is due to a high voltage battery junction box (HVBJB) failure. Ford needs to replace the HVBJB with an updated part and reprogram the BECM, at least. The dealer has no information on the replacement part, and has not associated TSB 21-2178 with the vehicle.”
Filed Sep 22, 2022
“We saw the recall warning and attempted to fix the issue but dealer stated it's been fixed over the air update. However, on July 21, there was a high voltage battery failure notice.”
Filed Jul 21, 2022
Should you keep driving it?
This page can't tell you that. 0 of 55 reports involved a crash. Owners who file are the ones who had a bad experience, and nobody checks their reports. If the problem affects steering, braking, power or a fire risk, treat it as a safety fault and have it inspected before a long or high-speed drive.
File your own report with NHTSA. Complaint counts are how a problem gets an investigation. How reports land on this sheet.
Guide Hybrid warning on the dash? Hybrid and EV battery complaints explained
Other problems on this car
- Forward collision warning goes off or the camera drops out 81 reports
- Battery dies or the car will not start 71 reports
- Adaptive cruise or lane keeping misbehaves 71 reports
- Infotainment, screen or backup camera fails 69 reports
- Engine stalls or loses power while driving 43 reports
- Brakes grind, pulse or wear early 31 reports