Mercedes CLA fog sensor problem

I have a similar Mercedes CLA and experienced comparable issues. The symptoms you describe align with a faulty automotive sensor, possibly the humidity sensor integrated within the fog sensor assembly. Have you checked the sensor calibration values using an appropriate diagnostic tool? Incorrect readings from sensor calibration can trigger these cascading failures within the climate control and heating systems. The electrical issue might extend beyond a simple cable, so look for corrosion or damage to the connector itself.

Thanks for the input. Where exactly is the fog sensor located, and can you describe the connector in more detail? Is it a standard type connector, or something specific to Mercedes?

The fog sensor is typically located near the base of the rearview mirror, integrated with the rain sensor. The connector is a multi-pin type, specific to Mercedes. Before replacing the sensor, I would suggest consulting a wiring diagram to confirm the pinout and voltage levels. A defective sensor can affect multiple systems. If you lack experience with automotive electrical systems, I would advise visiting a qualified workshop for proper diagnosis and potential sensor replacement.

Appreciate the advice. I took it to a workshop, and it turned out to be a corroded connector as suspected. They cleaned and replaced the connector for 95€. Everything is working now.