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.
Intake Air Control
The source of intake air is automatically controlled unless overridden by manual selection of recirculation. Under automatic control the automatic temperature control (ATC) module determines the required position of the recirculation door from the comfort strategy and the input from the pollution sensor (if fitted). The recirculation door is operated by an electric motor, which is controlled by hardwired analogue signals from the automatic temperature control (ATC) module. A potentiometer in the motor supplies the automatic temperature control (ATC) module with a position feedback signal for closed loop control.
Provided the intake air has not been manually selected to recirculation, the automatic temperature control (ATC) module adjusts the recirculation door to reduce the ram effect produced by the forward motion of the vehicle.
When the ignition switch is turned off, the automatic temperature control (ATC) module evaluates the ambient air temperature. If the ambient air temperature is less than a pre-determined value, the intake air source is set to recirculation, to prevent the ingress of damp air while the vehicle is parked.
When the vehicle is in the transportation mode, the automatic temperature control (ATC) module sets the intake door to recirculation every time the engine is turned off, regardless of the ambient air temperature.
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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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