Operation - 4.7L
Engine speed and crankshaft position are provided through the crankshaft position sensor. The sensor generates pulses that are the input sent to the powertrain control module (PCM). The PCM interprets the sensor input to determine the crankshaft position. The PCM then uses this position, along with other inputs, to determine injector sequence and ignition timing.
The sensor is a hall effect device combined with an internal magnet. It is also sensitive to steel within a certain distance from it.
On the 4.7L V-8 engine, a tonewheel is bolted to the engine crankshaft ( Fig 1 ). This tonewheel has sets of notches at its outer edge ( Fig 1 ).
The notches cause a pulse to be generated when they pass under the sensor. The pulses are the input to the PCM.