The DC/DC converter failed and caused the vehicle to immediately lose all power at a main intersection. My wife was driving the vehicle when this happened with out two children in the vehicle as well (ages [XXX] and [XXX]. Luckily, she was able to somewhat get out of intersection of a very busy road. The vehicle had to be towed to the Land Rover dealership. The part was covered by a factory extended warranty. There is an active recall for this part; however, this vehicle does not show to be in the recall. Since this part did fail, I wanted to file a complaint since it is not in the recall. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
2023 Land Rover Defender: sudden loss of power
9 of the 95 complaints about the 2023 Land Rover Defender describe sudden loss of power.
- owner complaints
- 9
- of this car's complaints
- 9%
- recalls
- 2
Sudden loss of power by model year
- 20252
- 20242
- 20239
- 20226
- 20201
What owners say
The vehicle experienced a sudden and complete electrical failure while driving, related to the DC converter. Warning lights did appear prior to the failure; however, I was driving down a mountainous road and do not recall the exact messages. Shortly after, the vehicle shut down and lost power, causing it to roll to a stop in active traffic. At the time of the incident, I was partially in the roadway and unable to safely move the vehicle out of traffic. The vehicle became inoperable and could not be restarted. I had two children and two dogs in the vehicle at the time. The vehicle had to be towed approximately two hours back home. The required part was on backorder for approximately two months due to so many vehicles having the issue, leaving my vehicle unusable for an extended period. This issue creates a serious safety hazard due to the sudden loss of propulsion and inability to move the vehicle out of traffic. Based on my research, this appears to be a known issue affecting multiple Land Rover Defenders. In attempting to locate the part sooner, we contacted several Land Rover dealerships, all of which indicated they had numerous Defenders awaiting the same repair due to part availability.
Car suddenly stopped and lost all power due to DC DC converter issue
The contact owns a 2023 Land Rover Defender. The contact stated that while driving approximately 55 – 60 MPH, the vehicle suddenly shuddered and vibrated with several unknown warning lights illuminated and flashing before the vehicle abruptly stalled and lost power in the middle of the freeway. The vehicle lost steering and braking functionality and was unable to accelerate. The vehicle failed to restart. The contact stated that several vehicles almost crashed into the rear of the vehicle, and a semi-truck came to a screeching halt behind the vehicle. The contact experienced an extreme panic attack and severe anxiety during the failure. The Emergency Services were called to the scene and with the help of the Fire Department, Police, and Ambulance Services, the vehicle was moved from the roadway to safety. The vehicle was later towed to the local dealer who diagnosed the vehicle and determined that the DC-to-DC converter had failed and needed to be replaced. The contact was informed that the part was on back order and that the vehicle could not be immediately repaired. The manufacturer was notified of the failure. The failure mileage was 40,000.
Car only has 42K miles on it- we were driving down the highway at approx 75mph, when the dash alarms started going off indicating an electrical system failure. A few minutes later all systems started flashing failures (lane keep assist system, braking system, etc)....then suddenly the gear box system failure alerted and the gears disengaged, the RPM's shot up and red-lined, and the CAR lost power in the middle of the highway. Fortunately we were able to get off to the shoulder without getting hit by a semi-truck. The car was completely dead. It had to be towed to a dealer, to find out that the DC/DC converter had failed- and these parts have been on back order for months- apparently this is a common issue with these cars, and people have been talking about it online...many have been without their car for 3-4 months waiting these parts.
I own a 2023 Land Rover Defender 130 that I purchased brand new. Since buying it, it has been back to the dealer many times for serious issues. The vehicle has had repeated cooling system failures, including replacement of all upper coolant hoses. Most recently it was at the dealer for coolant loss / no coolant, and the dealer diagnosed failed O-rings going into the turbo and repaired it. I was told this is a common issue but there has been no recall. Shortly after getting the vehicle back, while traveling with my family, I received a dashboard warning: “Stop safely – electrical fault.” Immediately after this warning, the vehicle lost power and died in the street with my family in the car, creating a major safety hazard and risk of being hit by traffic. The vehicle had to be towed. I am currently stranded in NY (away from home in MA) and the vehicle is now at a dealer here. It has been difficult to even get it seen by a technician, and we are supposed to return home tomorrow (Sunday). I have learned many other owners are experiencing similar “Stop safely” failures and it appears related to the P400 DC/DC converter. There have also been incidents where the steering wheel would not turn, and the only way to restore function was disconnecting the negative battery terminal to reset the vehicle computer, which is extremely dangerous. Additionally, the heated steering wheel overheated and burned a hole through the steering wheel and burned my hand while driving. The dealer replaced it under warranty, but the repair notes suggested the damage caused the heater issue, when the damage occurred because of the overheating/burn. This vehicle has had repeated safety-related defects involving the cooling system, electrical system, steering, and heated steering wheel, including sudden shutdown in the roadway with passengers. I request the federal safety agency investigate for a potential recall.
On December 29th 2025 my car displayed an alert "Electrical Fault Detected: Please Pull Car Over Safely". I was in rural New Hampshire at the time so continued driving (for about 5 minutes) until I lost all power steering, stability controls and ability to drive the car - luckily by this point I had made it to Gorham, NH. Luckily it was just me in the car and not my family as the temps were below 10 F that day and Land Rover couldn't get a tow until the next day. Since then the car had to be towed to Land Rover Bedford and has been in the shop since as they dont have any DC Converters (Part number 433123464) in the US. Apparently there are 1400 Land Rover Defenders all sat in garage lots as nobody can get this part in the US from the manufacturer. There is no ETA on when the part will arrive in the US and I will have my car back.
The DC/DC converter failed causing the generator not to charge. This caused the car to lose all power whilst I was driving the vehicle and come to a complete stop on an active road.
The vehicle experienced an electrical fault and shortly after receiving the warning on the dash, the vehicle completely lost power in the middle of traffic. The dealership has told me that the hybrid battery and DC converter both need to be replaced, but the DC converter is on indefinite back order. Based on information I’ve learned from others and I’ve heard from the dealership, Land Rover has been aware of this issue for about a year, but parts have been unavailable for several months. My dealership alone has several of the same vehicle suffering from the same problem, get Land Rover seems to have no path towards resolution.
Service bulletins that may apply
- Coolant Bypass Hose Leak
- Turbocharger Coolant Feed / Return Leak
- Arduous customer drive cycles have been found to accelerate the degradation of engine oil, leading to...
- Engine coolant may leak from the coolant bypass hose assembly
- Coolant may leak from the turbocharger coolant hose O-rings, resulting in engine coolant escaping into the...
- Engine coolant may leak from the coolant bypass hose assembly.
- Coolant may leak from the turbocharger coolant hose O-rings, resulting in engine coolant escaping into the...
- Coolant fan may continue running at high speed after ignition shut-off
Related recalls
Engine and engine cooling: engine: oil/lubrication: filter/screen
- What is wrong
- Jaguar Land Rover North America, LLC (Land Rover) is recalling certain 2023-2024 Defender, 2024 Discovery, Range Rover, Range Rover Sport, and Range Rover Velar vehicles. The oil filter housing can crack and leak oil into the engine compartment.
- Risk
- An oil leak in the presence of an ignition source such as hot engine or exhaust components, can increase the risk of a fire.
- Remedy
- Dealers will replace the filter housing, oil filter, and o-rings, free of charge. Owner notification letters were mailed June 27, 2024. Owners may contact Land Rover customer service at 1‑800‑637‑6837. Land Rover's number for this recall is N908.
Recall number 24V450000 · Recall details
Engine and engine cooling: engine: oil/lubrication
- What is wrong
- Jaguar Land Rover North America, LLC (Land Rover) is recalling certain 2019-2023 Range Rover Sport, 2020-2023 Range Rover, Defender, 2022-2023 Discovery, and 2023 Range Rover Velar vehicles. The engine cam carrier oil channel may be blocked, which can lead to an oil leak.
- Risk
- An oil leak in the presence of an ignition source can increase the risk of a fire.
- Remedy
- Dealers will inspect and replace the engine cam carrier and related components as necessary, free of charge. Owner notification letters were mailed March 29, 2023. Owners may contact Land Rover customer service at 1‑800‑637‑6837. Land Rover's number for this recall is N763.
Recall number 23V044000 · Recall details
Questions about the 2023 Land Rover Defender loss of power
Is sudden loss of power a common problem on the 2023 Land Rover Defender?
9 of 95 owner complaints about the 2023 Land Rover Defender (9%) mention sudden loss of power. The model year with the most reports is 2023.
Is there a recall or service bulletin for this on the 2023 Land Rover Defender?
There are 2 recalls and 75 service bulletins for the same area of the car. Check them below with your VIN.
Other symptoms on the 2023 Land Rover Defender
Windshield crack 9Headlights 7Overheating 6Power steering loss 5
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