Sensor, Crankshaft Position: Operation
Typical tone wheel (1) and Crankshaft Position (CKP) sensor (3) shown in illustration.
Engine speed and crankshaft position are provided through the Crankshaft Position (CKP) 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 CKP sensor (3) is a hall effect device combined with an internal magnet. It is also sensitive to steel within a certain distance from it.
A tone wheel (target wheel) (1) is bolted to the engine crankshaft. This tone wheel has sets of notches (2) at its outer edge.
The notches (3) cause a pulse to be generated when they pass under the sensor. The pulses are the input to the PCM.
Depiction of good camshaft and crankshaft square wave signals for 6 cylinder engines.