DTC P0335: Crankshaft Position Sensor Circuit: Description
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2002 GMC Savana Special, 2002 GMC Savana Camper Special, 2002 GMC Savana, 2002 Chevrolet RV Cutaway, and 2002 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
The Crankshaft Position (CKP) sensor is a hall-effect type of sensor that monitors the CKP and the speed. There are four teeth 90 degrees apart on the front of the crankshaft sprocket that induce a pulse in the sensor, this pulse is transmitted to the Powertrain Control Module (PCM). This signal allows the PCM to determine Top Dead Center (TDC) and RPM.