2006 Johnson SD 30 HP 4 Stroke Outboards Service Manual, PN 5006592, Page 71Get this manual
ENGINE CONTROL COMPONENTS
COMPONENTS
Flywheel
The flywheel contains permanent magnets which energize the charge coil, the crankshaft position sensor (CPS) coils, and the alternator statorOnce the flywheel exceeds minimum cranking RPM, the flywheel's magnetic lines of force pass through the ignition plate components to produce voltage in those circuits
Crankshaft Position Sensor (CPS)
There are two crankshaft position sensors installed below the flywheel rotorWhen the reluctor bar on the flywheel passes the sensors, signal (voltage pulse) is generated and sent to power packThis is the basic signal that is used to determine the engine speed and the crankshaft angleThe sensors send basic signal to the power pack for determining the ignition timing
11Permanent magnets (Not shown)