Lexus SC Climate Control Failure

I had a similar issue with my old Saab 9-3. The HVAC system went haywire. Have you checked all the relevant fuses and relays? A blown fuse can cause a whole system to shut down, and it's the easiest thing to check.

Good point. I've scanned for error codes but neglected the fuses. Which fuses specifically should I be targeting? Any hints on their location?

In my Saab, the fuse box was located in the engine compartment and another smaller one under the dashboard. Consult your Lexus manual for the exact location. However, I'd recommend visiting a workshop.

Thanks, I appreciate the tip! It turned out to be corroded electrical connectors, as suspected. Cleaned and reconnected, and everything's back online. The total repair cost was 95€!