Lexus SC Solar Sensor Fault

I encountered a similar issue on my previous BMW 5 series, although the exact model and year differ. The symptoms were similar: the climate control was acting erratically, and a fault code pointed towards the daylight sensor. In my case, the sensor was integrated into the rearview mirror assembly, which complicated diagnosis. Have you checked the sensor's wiring harness and connector for corrosion or damage? A high resistance connection can cause intermittent faults and incorrect readings. Also, does your Lexus have any TSBs (Technical Service Bulletins) related to climate control or sensor issues?

Cheers for the info. You mentioned high resistance... how did you track that down on your 5 series? I'm not seeing anything obvious on the Lexus, but I haven't put a meter on it yet.

The high resistance was diagnosed using a multimeter to measure the resistance of the wiring harness between the sensor and the climate control module. I also performed a voltage drop test to check for excessive voltage loss across the connections. Given the symptoms and fault code, and the potential for harness issues, I'd recommend a visit to a workshop with the appropriate diagnostic equipment. It could save you considerable time and potential component damage through misdiagnosis. The cable or plug connection of the component could be defective.

Appreciate the detailed response. I took your advice and got it checked out at a local shop. Turned out to be a faulty connection as you suspected, fixed for 95€. Thanks again!