Section 17 (Ignition System (Service Information) - 500L): Operation
WARNING: This page is about a different car, the 2017 Fiat 500L. However, it is still accessible from the selected car via links, so may be relevant.
The crankshaft position (CKP) sensor and camshaft position (CMP) sensor are hall effect devices. The CMP sensor and CKP sensor generate square wave pulses that are inputs to the powertrain control module (PCM). The PCM determines engine position from these sensors. The PCM calculates injector sequence and ignition timing from crankshaft and camshaft position.