P1490 indicates the ECM received an improper voltage signal from the vacuum cut valve bypass valve, which is located under and to the rear of the vehicle, not far from the coil spring. It's an electric solenoid valve that controls the flow of vacuum as part of the evaporative emissions system self-test. The usual cause is the solenoid sticks, meaning that the vacuum cut valve bypass valve should be replaced, but a short or open in the harness to it, or a poor connection in the harness connector, could set the code, as well.
