Circuit Operation

The crankshaft position sensor power is supplied from the MFI relay (terminal 1) to the crankshaft position sensor (terminal 3). The crankshaft position sensor (terminal 1) is grounded by the vehicle body. The PCM (terminal 45) supplies 5 volts to the crankshaft position sensor output (terminal 2). The crankshaft position sensor detects the crank angle (position) of each cylinder, and converts that data to pulse signals that are sent to the PCM.