Galant VR4 AWD L4-1997cc 2.0L DOHC Turbo (1992)
The four slits located at the outer circumference of the disc serve to detect the position of the crankshaft (and, therefore, the piston) relative to top
dead center. The ECU, based on this signal, determines the fuel injection timing, and also calculates the amount of intake-air, the timing of the
ignition signal, etc. for each revolution of the engine.