Mercedes GLS Hybrid High Voltage System Error Resolved

Whoa, sounds rough! I had a similar problem with my GLS, although the symptoms weren't quite as dramatic initially. It definitely sounds like a high-voltage system gremlin. First thing's first, have you checked the 12V battery? A weak 12V can cause all sorts of weirdness with the hybrid system, even triggering high-voltage errors. Also, any recent work done on the car, especially anything electrical? Could be a loose connection somewhere. Is it throwing any specific fault codes?

Thanks for the quick reply! I haven't specifically checked the 12V battery myself, but the error code does point towards the high-voltage system. No recent work done either. What was the eventual fix for your GLS? Was it an inverter issue, or something else?

Okay, so mine turned out to be a deeply discharged high-voltage battery, which then caused some voltage sensor weirdness. The car thought there was a major fault, hence the errors. I'd strongly advise getting it properly diagnosed at a workshop that knows hybrids inside and out. Messing with high-voltage stuff is seriously dangerous. They'll be able to pinpoint the exact cause, whether it's battery drain, a faulty inverter, or something else entirely. Could be electrical wiring too but voltage sensor issue is more likely. Better safe than sorry

Thanks, I appreciate the advice! I took it to my local mechanic, who specializes in electric vehicles. Turns out it was a heavily discharged battery, and they replaced a faulty voltage sensor. Total cost was around 290€. Car is running perfectly now! Thanks again for pointing me in the right direction.