Q: What is the purpose of the Crankshaft Position (CKP) sensor for Chevrolet C1500 and K1500?
A: The PCM gets a signal about the position of the crankshaft from the Crankshaft Position (CKP) sensor, which is used to determine the spark sequence for each cylinder, ignite at the right time-ignition timing, calculate engine speed and detect misfires. The notches cause fluctuation in the magnetic field as they pass the sensor and hence result in an oscillating voltage. If there is no input from this component, your ignition system will be disabled. The terminals and wires should be checked for looseness or breaks to test the sensor and also verify the voltage supply at the underhood electrical center. Fix it if there is wrong voltage that arises from it. Connect again(to check sensor operation), back probe on the yellow wire terminal and then crank engine (it should read 5.0 volts AC). Replace if there's no signal available. Whenever you change this part perform a Crankshaft Position Sensor Variation Learning Procedure to avoid false diagnostic trouble codes. Disconnect battery cable; raise vehicle and support using jack stands; remove skid plate if necessary; disconnect electrical connector; remove mounting bolt; install new sensor.