Crankshaft Position (CKP) Sensor
The CKP sensor is a hall effect sensor mounted on the engine block adjacent to a trigger wheel located on the crankshaft. By monitoring the crankshaft mounted trigger wheel, the CKP is the primary sensor for ignition information to the PCM. The trigger wheel has a total of 58 teeth spaced 6 degrees apart with 2 empty spaces. As the crankshaft rotates, the CKP sensor produces a sharp square wave and it detects the missing teeth when the expected change in the output signal is not produced within the expected time duration. By monitoring the trigger wheel, the CKP sensor signal indicates the crankshaft position and speed information to the PCM. By monitoring the missing teeth, the CKP sensor is also able to identify piston travel in order to synchronize the ignition system and provide a way of tracking the angular position of the crankshaft relative to a fixed reference. The PCM also uses the CKP signal to calculate engine RPM, fuel timing, fuel quantity, duration of the fuel injection and to determine if a misfire has occurred by measuring rapid decelerations between trigger wheel teeth.