Where is the expansion valve on a 2007 Mazda 3?

The expansion valve on a 2007 Mazda 3 is typically located within the engine compartment, specifically near the firewall, attached to the evaporator core housing. It is usually mounted on the refrigerant lines that connect the evaporator to the condenser. Accessing it may require removing certain components for better visibility and reach. Always consult the vehicle's service manual for precise location and procedures.