Prius electrical malfunctions and error messages

Hey there, sounds like a pain! I've heard of similar issues in Priuses around that year. First thing, have you checked the voltage of the auxiliary battery? A healthy one should be around 12.6V when the car is off. Also, are there any specific error codes showing up? Knowing those could point us in the right direction. Could also be a bad connection somewhere. Give the battery terminals a clean and make sure they're tight.

Thanks for the quick reply! I haven't checked the voltage yet, but I will do that. Where exactly can I find the auxiliary battery in the Prius, and how do I check the error codes myself without special tools?

No worries! The auxiliary battery is usually in the back, on the right-hand side under the trunk floor. As for the error codes, you'd ideally need an OBD2 scanner. Some auto parts stores will read them for you for free. While cleaning and checking is a good start, those error messages and your symptoms do suggest it's probably the battery itself if it's never been replaced. Honestly, for something like this, especially with electrical gremlins, it might be worth getting it checked out by a workshop. Save yourself the headache.

Thanks for the advice! I took it to a local garage and they confirmed it was the auxiliary battery. A new one cost me 290€ including fitting, and all the errors are gone now. Appreciate the help!