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.
Air Distribution System: RECIRCULATION
The recirculation damper regulates the amount of incoming fresh air. The recirculation function makes it possible to prevent outside air from entering the passenger compartment, for example when the ambient air is contaminated with exhaust fumes, smoke, etc. This function can also be used for rapid heating or cooling of the passenger compartment.
If the recirculation function is used for an extended period, the air humidity in the passenger compartment increases. This is due to the moist air exhaled by the passengers. This can result in mist on the windows.
In the max. cooling control position, approximately 85% of the incoming air is taken from the passenger compartment and approximately 15% from outside. This produces more rapid cooling of the passenger compartment air.
In vehicles with an air quality system (AQS), the transition to recirculation takes place automatically if the level of contaminants in the outside air increases.
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.
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