This flashes it continuously once the key is turned on to the Accessory position (even without the engine running). It doesn't go off once the engine's running. It'll only go off when the ignition is turned off. I tried the little switch under the dash but if I flick it in the other direction, the "check engine" light stays on continuously.
remove the fuse from the diagnostic fuse location in the fuse panel. it shouldnt blink at all then. the diagnostic location is a stand alone location on the left side of the fuse panel if i remember correctly but i could be wrong. check owners manual.