Make sure you have a good and decently charged battery. Turn the key to the run position, but don't crank or start the engine. Leave the key on for at least 90 seconds. That's it. If you have the hood open and you are listening, you will probably hear the calibration take place at some point in time during that 90 second period, usually fairly early into the process. You'll hear a little change in the character of the buzzing noise emitting from the actuator, followed by at least one, and on rare occasions, two distinct metallic "clack" sounds as a the mechanical end stops of the throttle plate are "learned" by the control unit...