According to this link: How does ECO mode change my 2014 Corolla driving experience and how do I operate it?
How does ECO mode change my 2014 Corolla driving experience and how do I operate it?

ECO mode reduces throttle response to help you accelerate slowly and smoothly. It also modifies air conditioning response to reduce the drain on engine power. Driving in this mode will improve fuel economy.

To operate, press the Eco Mode button behind the shift lever. An Eco Mode indicator appears in the instrument panel. Your Corolla will stay in Eco Mode until you press the button again or turn the ignition off and back on.

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So it makes a naturally laggy throttle even less responsive. Eco mode pa more.