Faulty Engine Control Module (ECM)
Engine Control Module (ECM) harness is open or shorted
Engine Control Module (ECM) circuit poor electrical connection
Engine Light ON (or Service Engine Soon Warning Light)
Automotic Transmission To Engine Control Module Signal ‘A’ Input Low is the generic description for the P1681 Acura code, but the manufacturer may have a different description for your model and year vehicle. Currently, we have no further information
about the P1681 Acura OBDII code.