2006-2010 Suzuki DF150 / DF175 4-Stroke Outboards Service Manual, Page 71Get this manual
ENGINE CONTROL SYSTEM
ECM MAIN RELAY The ECM main relay is installed in the fuse boxWhen energized by turning the ignition switch ON, circuit is formed which supplies battery voltage to the ECM, fuel injector, ignition coil, IAC valve, CMP sensor, high pressure fuel pump, OCV (Oil control valve) and VSV (Vacuum switching valve)1 1ECM main relay 2Fuse box 2
CRANKING SWITCH SIGNAL The ECM detects the engine being started by the position of ignition switch keyWhen the ignition key is turned to ST position, voltage (12 V) signal is input to the ECMThe ECM in turn controls the actuators for ignition, fuel injection, IAC, etcto the starting modeWith the key is turned to IG position after the engine has been started, the input voltage becomes approx1.4 V