Megane high voltage system error

Sounds familiar. I had a similar problem with my older Polestar. It turned out to be a heavily discharged battery triggering a system malfunction. Have you checked the battery's voltage? It could also be related to the inverter. Check for any battery warnings or electrical fault codes beyond the main high-voltage error.

Thanks for the quick reply! Where exactly should I be checking for these other fault codes, and is there a way to test the battery myself or is it better to take it to a workshop? I don't have any specific tools, but I'm pretty handy.

You'll need an OBD2 reader that can access the electric system's diagnostic codes. Without one, you're shooting in the dark. You could visually inspect the battery for any obvious damage, but testing its actual capacity requires specialized equipment. I'd recommend taking it to a workshop equipped to diagnose high-voltage systems. I had to do that with my Polestar. It's not worth risking further damage or personal injury.

Alright, appreciate the advice. Dropped it off at the shop, and they confirmed it was indeed a defective battery cell. The cost for the repair is estimated to be around 290€. Thanks for pointing me in the right direction!