2021 Ford F-150 Hybrid electrical system problems

“My 2021 F-150 PowerBoost hybrid repeatedly lost propulsion while traveling on the highway in early October 2026, including four incidents on one trip around October 3. At approximately highway speed, the tachometer dropped to zero while the selector remained in D, and the truck coasted as if in neutral. There were harsh shifts around 9th/10th gear and difficulty accelerating beyond approximately 70 mph. A vehicle warning appeared. Disconnecting and reconnecting the battery temporarily restored operation. Sudden loss of drive power in highway traffic created a collision risk. The underlying cause has not been independently established. A Ford dealer's October 2026 inspection recorded an internal transmission hydraulic leak, clutch-disconnect trouble codes suggesting a hybrid drive unit concern, a recommendation to replace the transmission with the hybrid drive unit, and high-voltage battery cell-balance DTCs. More recently electric-driving mileage has remained at zero and the gasoline engine continues running while stationary. Severe shifting and vibration had varied between 2H and 4A modes. Around June 2025 the vehicle also stopped operating and was towed to…”

“I picked up my F-150 Powerboost from the Ford dealership after getting and oil change. Recorded mileage was 100,385 (just 385 miles out of the 100,000 EV warranty. Just 2 hours after getting it back the check engine light came on for P0B24 for hybrid battery failure. The Ford dealership diagnosed the issue and confirmed the entire hybrid battery has to be replaced. I requested Goodwill assistance from Ford being that it was <500 miles out of warranty. Ford denied the request immediately. The Ford service department wrote them an email with official confirmation of the issue and the timing of the issue starting. Ford denied their request for Goodwill assistance/financial help within 20 minutes of the request. The repair is $5,000+ out of pocket.”

“The vehicle is currently at Kayser Automotive Group located at 2303 West Beltline Hwy Madison, WI 53713, their direct line is [XXX], since the diagnoses of the corrosion of the DCN. SYSTEMS & COMPONENTS THAT FAILED: A faulty or clogged engine bay drain plug failed to divert water, causing significant water accumulation that routed into the interior cabin. This water intrusion directly soaked interior carpeting and exposed the Data Communication Network (DCN) connector and Body Control Module (BCM) wiring harness to moisture, resulting in severe pin corrosion and electrical communication faults. The vehicle and all affected components are fully available for inspection upon request. SAFETY RISK: The DCN connector and Body Control Module control critical vehicle operations, exterior lighting, instrument clusters, and safety/driver-assistance systems. Water corrosion on these communication buses causes unpredictable, uncommanded electrical failures and module communication dropouts while operating the vehicle at speed, creating a severe crash hazard to occupants and surrounding traffic. DEALER CONFIRMATION & INSPECTIONS: The issue was physically inspected and…”

“Good Afternoon. The Pro Power Onboard high-voltage electrical system has experienced a permanent malfunction, locking out with a "Ground Fault Detected" warning. The vehicle is a 2021 Ford F-150 Rocky Ridge conversion. This failure stems directly from a defective or incomplete execution of Safety Recall 23S35 (NHTSA Campaign 23V613000).The initial remedy applied by the dealership consisted only of adding protective tape to the rear wiring harness. However, due to the increased travel and ride height of the official Rocky Ridge suspension lift, the wiring harness pulled out of its factory retaining side clip. This caused excessive tension and stretching on the high-voltage lines, completely exposing the bare interior colored wires and leaving them vulnerable to road moisture and friction against the metal frame.The system now triggers a permanent short-to-ground error, creating an imminent risk of an electrical short circuit or vehicle fire under the high-voltage (120V/240V) lines. The Ford dealership and corporate customer care refuse to remedy this recurring safety hazard under the recall warranty because it was previously marked as completed, even though the…”

“2021 Ford F-150 PowerBoost Hybrid, VIN [XXX]. At 112,000 miles — just 1,000 miles outside of warranty — the vehicle experienced catastrophic failure of the hybrid battery system. Ford's own technician diagnosed a short in the high voltage battery system that caused damage to the hybrid electric drive unit. Repair estimate is $19,000. Ford declined goodwill warranty coverage despite the vehicle being only 1,000 miles outside warranty and the failure occurring on a known problematic system. This is a $72,000 vehicle purchased new in 2021 that has suffered a catastrophic drivetrain failure at only 3 years old. The high voltage battery short and hybrid drive unit failure represent a potential safety hazard to drivers and other motorists.”

“Vehicle Information 2021 Ford F-150 PowerBoost VIN: [XXX] Complaint Description While driving approximately 70 mph on a highway, my 2021 Ford F-150 PowerBoost suddenly displayed a “Stop Safely Now” message and immediately lost propulsion. The engine shut down without warning while I was in active traffic. After the shutdown, the vehicle automatically shifted into park and would not allow me to shift into neutral. This left me unable to move the vehicle out of a live traffic lane. I was forced to shut the vehicle off while still in a dangerous roadway position. This incident created a serious safety hazard, as I was traveling at highway speed and could have been rear-ended due to the sudden loss of power and inability to move the vehicle. This issue appears to match Ford Technical Service Bulletin (TSB) 23-2317, which describes “Stop Safely Now” warnings, no-start conditions, and gateway module (GWM) software faults. This indicates a known defect that can cause sudden loss of propulsion. A claim has already been opened with Ford Motor Company under case number [XXX], and the vehicle is currently at a Ford dealership for diagnosis. At this time, the issue has not…”