Circuit Description
WARNING: This page is about a different car, the 2007 Suzuki SX4. However, it is still accessible from the selected car via links, so may be relevant.
When the ignition switch is turned ON, the main relay turns ON (the contact point closes) and the main power is supplied to ECM. And then ECM supplies 5 V power to each sensor (EVAP leak check pressure sensor, A/C refrigerant pressure sensor, APP sensor and TP sensor).
If 5 V power circuit to each sensors from ECM is shorted to ground, ECM stops engine and emission control operation.