Does this button activate anything other than the ECT light on dash? There’a no more power or earlier downshifting.
What that button usually does is change the upshift points. Watch your tach with the button in the ‘economy’ position and at a medium set throttle, the shift points will be lower than they would be in the ‘power’ position. Try various throttle positions. If you don’t see any difference, you might check with the dealer to see what the programed transmission personalities are.