Circuit Operation

WARNING: This page is about a different car, the 2008 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.

ASC-ECU contains the power supply circuit (terminal No. 1) for the motor. The pump motor is energized by the pump motor switch, which is incorporated in ASC-ECU.
The pump motor switch in ASC-ECU is turned off at all times unless during the motor solenoid valve check performed when the vehicle is started.
ASC-ECU activates the pump motor by turning on the ECU built-in pump motor switch.