Prizm L4-108 1.8L DOHC VIN 8 MFI (1998)
Crankshaft Position Sensor: Description and Operation
CrankShaft Position (CKP) Sensor
Crankshaft Position (CKP) Sensor
The crankshaft position (CKP) sensor is located in the cylinder block near the crankshaft pulley. The CKP sensor produces an alternating current signal
that increases in both frequency and amplitude as engine speed increases. The CKP sensor signal is sent to the powertrain control module (PCM) in order
to indicate RPM and crankshaft position. The PCM uses the CKP sensor signal along with the camshaft position sensor signal in order to determine the
following:
^
Calculate fuel injector pulse.
^
Establish piston position (top dead center) for ignition timing.
^
Start the ignition coil and fuel injection sequencing.
Operation
The CKP sensor signal rotor has 34 teeth and is mounted on the crankshaft behind the timing chain cover and the crankshaft pulley. When the crankshaft
rotates, the CKP sensor signal rotor teeth pass by the CKP sensor causing a fluctuation in the sensor's magnetic field. The fluctuation in the magnetic
field induces a voltage in the CKP sensor circuitry. The sensor sends this signal to the PCM at rate of 34 signals per crankshaft revolution.
