Lexus RX electrical issues

Interesting. I own a Lexus RX too, although I'm not sure about the manufacturing year, and I encountered comparable problems not long ago. The error message accompanied a noticeable voltage drop, especially during startup. Did you measure the voltage of the auxiliary power source? It might be a low voltage issue, indicating battery failure.

Thanks for your reply! I haven't measured the voltage myself, as I don't have the necessary equipment. But given the symptoms, do you think it's definitely the auxiliary battery causing all these problems?

While I cannot provide a definitive diagnosis without proper testing, my experience strongly suggests it's a battery issue. Given the error messages and starting problems, a failing auxiliary battery is the most probable cause. Considering the potential for further electrical damage, I would recommend taking it to a qualified workshop for inspection and potential battery replacement. I eventually had to pay 290€ for the repair.

Thank you so much for sharing your experience! It's really helpful to know someone else has faced a similar issue. I'll definitely take it to a workshop to have the auxiliary battery checked and replaced if necessary. I appreciate your advice!