Prelude L4-1958cc DOHC (1989)
Crankshaft Position Sensor: Description and Operation
Fig. 26 TDC/CRANK Sensor
The CRANK sensor determines timing for the fuel injection and ignition for each cylinder, and also detects engine rpm.
The TDC sensor determines ignition timing at start-up (cranking) and when crank angle signal is abnormal.
