Overview
Across the EV industry, mild-hybrid vehicles are becoming more common, and so are the challenges that come with them. One issue we’re seeing repeatedly is a DC-DC converter fault affecting certain Land Rover mild-hybrid models. At LKQ Electriq, our Innovation team is actively developing a repair-led solution that helps keep vehicles on the road, reduces downtime, and offers garages a practical alternative to long waits for replacement parts.
The fault we’re addressing affects Land Rover models equipped with a 48‑volt mild-hybrid system, including:
- New Defender
- Evoque
- Discovery Sport
- Velar
The issue centres on a DC‑DC converter, which is a critical component that manages power between the 48‑volt and 12‑volt systems. When the converter fails, the 12‑volt battery is no longer charged correctly. As a result, the driver is typically greeted with a dashboard warning stating “Charging system fault”, alongside fault code P0D33 (DC‑DC converter current high circuit short to ground).
In short: the vehicle may still start, but it won’t stay reliable for long.
This isn’t a rare or isolated failure. We’re seeing it regularly across the industry and replacement units are often on extended backorder. Vehicles are ending up:
- Off the road for weeks or months
- Stuck at main dealers awaiting parts
- Parked up on fleet yards unable to operate
For garages, it’s frustrating. For customers, it’s unacceptable. For fleets, it’s expensive. A DC-DC converter fault doesn’t just create a technical problem, it creates a commercial one.
From the start, our focus has been clear on making this repairable. Rather than relying on the vehicle to test the unit, our first challenge was developing a bench-testing process that allows us to diagnose DC‑DC converters independently. That step is crucial if garages are going to remove the component, send it to us, and get a confirmed repair back, without tying up ramps or vehicles.
Once bench testing was established, we moved into fault isolation. We’ve now identified that the issue is typically an internal circuit board fault, not something external or vehicle-related. This discovery opened the door to a viable repair strategy.
So far, we’ve achieved several key milestones:
- Confirmed the common internal failure point within the converter
- Developed a repeatable bench-testing solution
- Verified fault behaviour without needing the vehicle present
- Begun validating repair methods to prevent recurrence
We’re now in the stage of gathering additional faulty units. This allows us to confirm variations of the failure mode and ensure that our repair process covers all known causes, not just one.
In R&D terms, we have made good progress, but thorough validation is essential.
What makes this project different isn’t just the fault, it’s the service model. We’re working toward a B2B repair solution where:
- Garages remove the DC‑DC converter
- Send it directly to us here at LKQ Electriq
- We repair, bench-test, and return it
- The garage refits the unit and keeps the labour
That approach keeps vehicles moving, reduces reliance on new parts, and gives workshops a practical alternative when faced with a DC-DC converter fault and no OEM availability.
It’s a scalable model and one we believe represents the future of EV and hybrid repair.
Our End Goals
- Deliver a cost-effective, reliable DC‑DC converter repair
- Reduce vehicle downtime caused by parts backorders
- Support independent garages and fleets with real solutions
- Create a repair process that’s efficient, repeatable, and scalable
Longer term, the same repair principles can be applied to other brands and platforms as similar failures emerge.
Next Steps
Next, we need more faulty units. Additional converters allow us to complete fault mapping, finalise the repair procedure, and accelerate release of this as a service.
Once validated, we aim to roll this out as a supported B2B repair offering, giving the industry a proven alternative to waiting months for replacement parts.
If you’re dealing with a DC-DC converter fault and have a unit available, it could directly help bring this solution to market sooner.
