Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Humidity Sensor (Option, Only ECC 2008-)
The task of the humidity sensor (HUS) is to transmit information about the passenger compartment's humidity to the Climate control module (CCM).
The sensor is part of the optional system for air quality together with the Air quality sensor (AQS) and a particle filter.
The humidity sensor is via serial communication to the Central electronic module (CEM), which transmits the information to the Climate control module (CCM) on the CAN network.
All information processing then occurs in the Climate control module (CCM).
The sensor is in the holder for the rear view mirror and is powered and diagnosed by the Central electronic module (CEM).
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.