ect power light came on and want go off

whats an 'ect light"

we need more info

model year mileage location

You must have pressed the ECT power button by mistake, you didn't say what car you have, so look around the dash or the transmission lever area.

That changes the auto tranny's shift points for faster pickup, but burns more gas.

The ECT button concerns the Electronically Controlled Transmission. It changes the personality of the trans from the default (Economy) mode to the Power mode -- sometimes thought of as the Performance Mode.

On our Tacoma PreRunner, the button to control the ECT is on the far left of the dashboard, near the driver-side door. When the button gets pressed, ECT is selected in the Power mode. This means that the shift points are altered in the transmission, each gear is carried longer -- higher revs -- instead of short-shifting to use less gas. It does not harm the trans or th eengine in any way to leave the button with the ECT light constantly on. Having said that, the light is supposed to turn off when you shut the motor off, then remain off the next time you start the vehicle. ECT is a feature that one must select each time they start the vehicle and prepare to take a trip.

The ECT light is also a trouble light. If the light is flashing, you need transmission service. You didn't say if the light is flashing, but if it does not reset when you shut the motor off, then there is a good chance the transmission is trying to tell you something. this would be a very good to drag the Owner's Manual out of the glovebox and look through it.