Lexus LS Generator Fault

Sounds like a potential charging system issue. The symptoms you describe—reduced power, warning light, starting problems, flickering lights, and a stored generator fault—all point in that direction. A failing generator (often called an alternator in non-hybrid vehicles) can definitely cause these problems. The hybrid system makes it more complicated, though. Has the 12V battery ever been replaced? A weak 12V can cause all sorts of weirdness in modern car electronics.

Thanks for the quick reply! I'm not sure about the 12V battery history, I bought the car used a few years back. How can I check whether this battery is still good enough, and could a defective battery really be the cause, even when the car can still start?

A weak 12V battery in a hybrid can cause a cascade of problems because it powers the car's computer systems before the hybrid system kicks in. Even if it starts the car, a voltage drop can trigger false error codes and disrupt normal operation. Get the 12V battery load tested. Many auto parts stores do this for free. If it tests okay, then you are probably looking at a defective generator and a costly repair. Given the symptoms and error code, I would strongly advise having a professional mechanic diagnose the charging system. Replacing the generator yourself on a hybrid can be tricky, especially with high voltage components involved. A faulty generator can over time damage other parts, like the hybrid battery.

Appreciate the detailed advice. Looks like I'll have to bite the bullet and take it to a trusted workshop for a proper diagnosis. From the symptoms and the error codes I got, a defective generator is a pretty plausible explanation. The mechanic quoted around 960€ for the repair, including the generator replacement. I'll definitely have them check the 12V battery as well, just to be sure. Thanks again for the help!