Viano Diesel Solar Sensor Fault

A solar sensor fault on a Viano/Vito could impact your heating. These sensors, sometimes called sunlight or HVAC sensors, are part of the automatic climate control system. They help the system determine how much solar radiation is entering the cabin, adjusting the heating and cooling. If the sensor reports incorrect data, the system might think it's cooler, reducing heating output. First, locate the solar sensor on your dashboard – a small, dark dome. Inspect the wiring and connector for damage, corrosion, or loose connections. Have you checked the fault code with a diagnostic tool? Knowing the code could provide more clues.

Thanks for the explanation! That makes sense. I used a generic OBD2 reader, and it gave me a generic 'solar sensor fault' message. Nothing specific. Where should I look for this sensor? I had a quick look, but I can't see anything obvious. Is it easy to get to the wiring without dismantling the dashboard?

A generic OBD2 reader might not give you the specific Mercedes fault code. A Mercedes specific diagnostic tool will give you a more precise code. It's typically located in the center of the dashboard, near the base of the windshield. Accessing the wiring can be tricky; sometimes you can gently pry up the sensor housing, but often you need to remove a section of the dashboard. Given the potential for damage and the repair cost you mentioned, it might be more cost-effective to have a workshop diagnose it properly with the correct tools. They can pinpoint the exact fault and replace the sensor or repair the wiring.

Right, I understand. Thanks for the advice. I think I'll take it to a local garage. Poking around myself could cost more. Hopefully, it's just a loose connection. Appreciate the help!