On Board Chargers
Diagnose and repair on-board charger faults to restore reliable AC charging, with robust validation and clear reporting.
On-board charger (OBC) failure
The on-board charger (OBC) is responsible for converting AC power from a charge point into DC power to charge the high-voltage battery. When the OBC develops a fault, vehicles often struggle to charge on AC, may display charging or EV system warnings, or may intermittently stop charging.
Our on-board charger repair service focuses on confirming the true failure mode (not just the symptom), repairing or replacing the appropriate components, and validating the charging system under real-world conditions. Where relevant, we also check for related issues that can mimic OBC failure (e.g., charge port issues, wiring faults, HV interlock problems, coolant ingress, or communication faults).
Selection of Covered Vehicles - On-Board Charger Repairs
View a selection of vehicles that have an On-Board Charger repair solution
BMW
- BMW 3 Series 2017-2023
- BMW 5 Series 2017-2023
Note: BMW refer to the OBC module as a KLE
Jaguar
- iPace 2018-2024
Nissan
- Nissan Leaf 2010-2017
Note: Nissan OBS's are located within the Power Delivery Module (PDM)
Tesla
- Tesla Model S (2012–present)
- Tesla Model X (2015–present)
- Tesla Model Y (2019–present)
- Tesla Model 3 (2017–present)
Can't find your vehicle?
The vehicles listed are a selection of On-Board Charger Repairs. Please contact us if your vehicle is not listed.
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Case Studies
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Common Symptoms
AC charging will not start
The vehicle refuses to begin charging on AC, often with an error on the car or the charge point.
Charging starts then stops
Charging begins normally but stops after a short time, sometimes repeatedly, suggesting intermittent faults or thermal/protection shutdown.
Reduced AC charge rate
The vehicle charges significantly slower than expected, potentially due to partial phase loss, internal module faults, or derating.
Charging-related warning lights / fault codes
Dash warnings and stored fault codes may indicate charger internal faults, insulation/isolation issues, or communication errors within the charging system.
Vehicles Affected
- EVs and PHEVs with liquid-cooled or integrated OBC assemblies
- Vehicles with combined OBC + DC-DC converter units (architecture-dependent)
- Platforms known for coolant ingress risk into charger housings (vehicle-dependent)
What's Included?
Safety-first assessment and confirmation
We confirm the charging complaint and check for obvious external factors (where applicable) before proceeding with repair decisions.
Root-cause diagnostic approach
We use systematic testing to distinguish OBC faults from upstream issues (charge point, cable, inlet/port, HVIL, wiring, control faults).
Repair / replacement and re-integration
We repair or replace the relevant OBC components/assembly and re-integrate the unit correctly within the vehicle’s HV and communications systems.
Validation and reporting
We validate outcomes (e.g., consistent AC charge acceptance, stability under load, and absence of relevant fault codes) and provide a clear summary of findings and work completed.
All work is backed by a 12-month warranty covering both parts and labour, giving you peace of mind and confidence in the quality of our service.
Very pleased with the service I received. Good communication from Adam throughout the whole process. My car has been repaired for under half the price that BMW were quoting.