Subaru LEGACY 2002 Quick Reference Index page 204

Fuel Injection (Fuel System)
D: CRANKSHAFT POSITION SENSOR
! The crankshaft position sensor is installed on the rear end of the cylinder block. The sensor gen-
erates a pulse when one of the teeth on the perimeter of the crankshaft plate (rotating together
with the crankshaft) passes in front of it. The ECM determines the crankshaft angular position by
counting the number of pulses.
As the crankshaft rotates, each tooth of the crankshaft plate aligns with the crankshaft position
!
sensor so that the magnetic flux in the sensor's coil changes since the air gap between the sensor
pickup and the crankshaft plate changes. This change in magnetic flux induces a voltage pulse in
the sensor and the pulse is transmitted to the ECM.
(1)
(1) Crankshaft plate
(2) Crankshaft half rotation
SENSORS AND SWITCHES
FU-24
(2)
B2H3912B