Suzuki DF150 Service Manual page 72

ECM MAIN RELAY
The ECM main relay is installed in the fuse box. When ener-
gized by turning the ignition switch ON, a circuit is formed which
supplies battery voltage to the ECM, fuel injector, ignition coil,
IAC valve, CMP sensor, high pressure fuel pump, OCV (Oil con-
trol valve) and VSV (Vacuum switching valve).
CRANKING SWITCH SIGNAL
The ECM detects the engine being started by the position of
ignition switch key. When the ignition key is turned to ST posi-
tion, a voltage (12 V) signal is input to the ECM.
The ECM in turn controls the actuators for ignition, fuel injection,
IAC, etc. to the starting mode.
With the key is turned to IG position after the engine has been
started, the input voltage becomes approx. 1.4 V.
ENGINE CONTROL SYSTEM
1
1. ECM main relay
2. Fuse box
+12V
1
OFF
IG
ST
ECM
2
1. Ignition switch
2. Neutral switch
3
3. To starter motor relay
3-13
2