EC (Economy) Mode
WARNING: This page is about a different car, the 1997 Mercedes-Benz C280 and 1997 Mercedes-Benz C230. However, it is still accessible from the selected car via links, so may be relevant.
In economy setting, A/C compressor remains off. In any other setting, A/C compressor comes on when ambient temperature is greater than 41°F (5°C).
In ventilation mode, air is supplied from center and side dash panel registers. In heating mode, warm air is primarily supplied to foot area. Enough air is supplied to windshield and dash panel side registers to keep glass defogged in normal weather conditions. Air will be emitted from center dash panel register depending on interior temperature.
With low outside temperatures, fan operation is delayed until engine coolant temperature rises above set temperature.