The D4 light is blinking why. on 1991 Acura Legend

it just started today and I dont know how to get a code.

Asked by for the 1991 Acura Legend
Stored codes are displayed by a flashing LED on the ECU. When the CHECK ENGINE warning lamp has been on or reported on, lift or remove the carpet from the right front passenger footwell.
Turn the ignition switch ON; the LED will display any stored codes by rhythmic flashing.
Legend models are also equipped with a service connector in side the cabin of the vehicle. If the service connector is jumpered, the CHECK ENGINE lamp will display the stored codes in the same fashion. The 2-pin service connector is located under the extreme right dashboard.
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