After replacing the Air Contorol Valve, MUST perform the "ECU Initialization" procedure.
Otherwise trouble related with engine performance or emission control may occur until ECM learning about the component is over.
Turn ignition switch OFF.
Connect the GDS to Data Link Connector (DLC).
Turn ignition switch ON.
Select "Vehicle, Model year, Engine, System".
Select "Vehicle S/W Management".
Select "ECU Initialization".
Select "Throttle Valve (ACV) Change".
Perform the procedure in accordance with the message.