The ECON button turns the ECON mode on and off.
The ECON mode helps you improve your fuel economy by adjusting the performance of the engine, transmission, heating system*/climate control system*, and cruise control*.
Honda Civic Owners Manual. Resetting the Display
Reset the maintenance minder information display if you have performed the
maintenance service.
Turn the ignition switch to ON
and have
the vehicle at a complete stop.
Display the Maintenance Minder by
repeatedly pressing the (TRIP)
knob.
Press and hold the ...