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.
Electronic Automatic Temperature Control (EATC): Notes
2010 Ford Focus S, StandardSECTION Notes
WARNING: This page is about a different car, the 2010 Mercury Mariner and 2010 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The HVAC module analyzes input from the following major sources:
- Temperature, airflow mode, blower, A/C and RECIRC selection (made by the vehicle occupants)
- In-vehicle temperature sensor (non-hybrid only)
- In-vehicle temperature and humidity sensor (hybrid only)
- Ambient temperature sensor
- Sunload sensor (solar radiation sensor)
- Evaporator discharge air temperature sensor
- Vehicle speed
- Engine Coolant Temperature (ECT)
Using these inputs, the HVAC module determines the correct conditions for the following outputs:
- A/C compressor ON/OFF request
- Blower motor speed
- Temperature blend door position
- Airflow mode door position
- Air inlet door position
RENDER: 1.0x
NO RELATED
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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.