Civic Hatchback L4-1493cc 1.5L SOHC (D15B1) TBI (1990)
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, there 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.