Lanos S Hatchback L4-1.6L DOHC D-TEC MFI (1999)
Crankshaft Position Sensor: Description and Operation
This electronic ignition system uses a magnetic crankshaft position sensor mounted just ahead of the block below the intake manifold. This sensor
protrudes through its mount to within approximately 1.3 mm (0.05 inch) of the crankshaft reluctor. The reluctor is a special wheel attached to the
crankshaft pulley with 58 slots machines into it, 57 of which are equally spaced in 6 degree intervals. The last slot is wider and serves to generate a
"sync pulse." As the crankshaft rotates, the slots in the reluctor change the magnetic field of the sensor, creating an induced voltage pulse. The longer
pulse of the 58th slot identifies a specific orientation of the crankshaft and allows the powertrain control module (PCM)/engine control module (ECM) to
determine the crankshaft orientation at all times. The PCM/ECM uses this information to generate timed ignition and injection pulses that it sends to the
ignition coils and to the fuel injectors.
