Seat Formentor Hybrid High Voltage System Error

Sounds like a real headache! I had something similar happen with my Formentor. Was getting a high-voltage system error message too, and the engine kept cutting out. Did you notice any other weird electrical issues before this started? Like, maybe the lights flickering or the infotainment system acting up? Could be an inverter issue, or even something related to the electrical wiring.

Interesting, an inverter issue, huh? No, I didn't notice any flickering lights or infotainment problems. The only symptom was really the high-voltage system malfunction error and the engine shutting off. Do you think it’s more likely an inverter problem than just a simple battery drain?

Well, in my case, the initial error pointed towards the high-voltage system, and I was worried about the inverter. BUT, after a lot of troubleshooting, it turned out to be a faulty battery that was causing the whole chain of errors. Since you don't have any other electrical issues, I'd lean towards a battery drain or a defective battery. Still, you should take it to a qualified workshop and ask them to check the electrical wiring also. Why risk it?

Took it to a workshop, and they found a heavily discharged battery. They replaced it; the high-voltage system malfunction error is gone. Seems like the electrical fault was indeed a battery drain issue like you suggested. The final repair cost was 290€. Thanks again for your help!