Yaris Hybrid electrical errors

That sounds like a classic auxiliary battery issue, especially with those kilometers. Has the battery ever been replaced? These Yaris hybrids are quite sensitive to voltage drops. Low voltage can cause all sorts of seemingly unrelated electrical malfunctions. Before jumping to conclusions, have you checked the battery's voltage yourself? And are all the connections clean and tight?

Good shout on the battery replacement! I actually haven't replaced it since I bought the car. I'll check the voltage with a multimeter tomorrow. Where exactly should I check for voltage drop? Are there any specific points on the auxiliary battery or the car's frame I should focus on?

Given that it hasn't been replaced, it's almost certainly the culprit, especially considering the error codes and symptoms you're experiencing. While checking the voltage is a good diagnostic step, at this point, I'd strongly recommend taking it to a qualified mechanic. A weak auxiliary battery in these hybrids can cause unpredictable power management issues. Continuing to drive with it could potentially damage other components. It's always best to err on the side of caution with hybrid systems.

Thanks a million for the advice! Dropped it off at the local garage, and you were spot on – it was the auxiliary battery. Cost me 290€ for a new one and installation. Feeling much better about the car now! Appreciate the help!