Toyota Prius 1.8 Hybrid (2015)
Toyota Prius — mystery hybrid warning light in Southampton
The hybrid system warning light would come on after 20 minutes of driving, then clear after a restart. A main dealer had quoted for a full hybrid battery…
The fault
The hybrid system warning light would come on after 20 minutes of driving, then clear after a restart. A main dealer had quoted for a full hybrid battery replacement.
Diagnosis
We ran a full high-voltage diagnostic and battery health check. The battery blocks were healthy — the fault was a failing DC-DC converter under thermal load, not the traction battery.
Repair process
Replaced the DC-DC converter, cleared the stored codes, and carried out a full hybrid system health check and cooling system inspection to confirm no underlying cause.
Tests & Handover
Extended road test with the hybrid system monitored live — no warnings, converter operating within spec. Customer saved from an unnecessary battery replacement worth thousands.
Gallery
Repair summary
- Vehicle:
- Toyota Prius 1.8 Hybrid (2015)
- Problem:
- The hybrid system warning light would come on after 20 minutes of driving, then clear after a restart.
- Diagnosis:
- We ran a full high-voltage diagnostic and battery health check.
- Repair:
- Replaced the DC-DC converter, cleared the stored codes, and carried out a full hybrid system health check and cooling system inspection to confirm no underlying…
- Result:
- Extended road test with the hybrid system monitored live — no warnings, converter operating within spec.
- Location:
- Southampton, Hampshire · BMS Garage
Same fault on your car?
Need the same repair?
See our Hybrid & EV Diagnostics service in Southampton.
View Hybrid & EV DiagnosticsGot a gearbox or hybrid fault others can't fix? Message us on WhatsApp — we'll diagnose it properly.
Message us on WhatsApp