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.
Regulating Humidity
The humidity sensor checks for condensation on the windscreen. In the event of a risk of condensation, it sends a signal via serial communication to the Central electronic module (CEM) (4/56), which forwards the signal to via the CAN network to the Climate control module (CCM). Climate control module (CCM) (3/112) receives the signal and reacts as follows:
- Dries the incoming air by reducing the set point of the evaporator (for ECC).
- Starts taking in more fresh air. If the Air quality sensor (AQS) (7/159) has transmitted signals to the Climate control module (CCM) to close the fresh air damper, the Climate control module (CCM) ignores the signal and opens the fresh air damper.
- Transmits signals to the Damper motor module (DMM) defroster (6/102) to increase the air flow on the front windscreen.
- Increases the speed of the blower fan by transmitting a signal to the Central electronic module (CEM).
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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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.