Crankshaft Position Sensor: Description and Operation

CRANKSHAFT POSITION (CKP) SENSOR

The CKP sensor is a permanent magnet generator, known as a variable reluctance sensor. The sensor is mounted in the left rear of the cylinder block. A crankshaft mounted reluctor wheel that has sixty slots, two of which are missing, alters the magnetic field of the sensor. This arrangement results in the CKP sensor output of fifty-eight pulses per crankshaft revolution. The two missing slots represent the position of the cylinder 1 and cylinder 4 pistons 84 degrees before top dead center (BTDC). The CKP sensor is connected to the ECM by a signal circuit and a low reference circuit. Both CKP sensor circuits are protected from electromagnetic interference by a shielding ground circuit. The shielding circuit is grounded through the ECM. Using the CKP signals in conjunction with those from the CMP sensor the ECM determines the engine position with great accuracy.