Sonata L4-2.4L (1990)
Photoelectric Signal Pattern
No.1 Cylinder TDC Signal:
Top dead center is detected by the signal obtained through the one inner slit of the disc. The ECU, based upon this signal, determines which of the four
pulses from crank angle sensor is the signal for the #1 cylinder.
Crankshaft Angle Signal:
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.
