Avensis Lighting Fault

Sounds frustrating! I had a similar issue with my old 2014 Opel Astra a few years back. The dashboard lights would flicker randomly, and sometimes the headlights would just decide to party on their own. The error memory stored a similar error. Usually, it's a cable or plug connection of the component that is defective. Have you checked the connections to the headlight switch? A loose or corroded connector can cause all sorts of weirdness. Also, are the dashboard lights on when the headlights switch on?

Thanks for the suggestion! I haven't actually checked the connections to the headlight switch yet - where exactly is it located and how do I get to it on the Avensis? And yes, dashboard lights are also coming on with this issue. Is it safe to keep driving it like this, or could it cause more damage?

On most cars, the headlight switch is part of the steering column control module; on the Avensis it should be the same. Access is usually straightforward, but disconnecting the battery before poking around is crucial to avoid any shorts or airbag issues. Since the dashboard lights are involved, it reinforces my suspicion of a wiring issue affecting multiple circuits. Regarding safety, driving with electrical faults can be risky. I would recommend that you take it to the workshop. I ended up paying 110€ for the repair (the price depends on the workshop). It's better to be safe than sorry, especially with electrical problems!

Thanks a bunch for your help and sharing your experience! Looks like I'll bite the bullet and book it in to get looked at. They quoted me 95€ for replacing the switch so hopefully that will solve the issue. I appreciate the advice!