Crankshaft Position Sensor: Description and Operation

TDC/CRANK/CYL Sensor:

This sensor, contained in the distributor housing, consists of three rotors, TDC, CRANK, and CYL, their associated pickup coils, and a common shaft. Since the rotors are coupled to the cam shaft, they turn together as a unit as the cam shaft rotates.
The CRANK sensor determines timing for fuel injection and ignition of each cylinder and also detects engine rpm. The TDC sensor determines ignition timing at start-up (cranking) and when crank angle is abnormal. The CYL sensor detects the position of No. 1 cylinder for sequential fuel injection to each cylinder.