The system attempts synchronization and looks for an increase in engine speed indicating the engine started. The Camshaft Position sensor 1X signal is used by the PCM to determine if the cylinder at top dead center is on the firing stroke, or the exhaust stroke. The PCM can determine top dead center for all cylinders by using the Crankshaft Position sensor 24X signal alone.
Observe that as long as the Crankshaft Position sensor 24X signal is available, the engine will start. The 4X signal also provides a tach signal for any device which requires one. The PCM uses the 4X signal for internal calculations. The PCM also calculates a 4X signal from this information. The PCM uses this 24X signal in combination with the Camshaft Position sensor 1X signal in order to accurately determine crankshaft position. The sensors internal circuitry detects this and produces a signal which the PCM reads. As the crankshaft rotates, the reluctor wheel teeth interrupt a magnetic field produced by a magnet within the sensor. The PCM uses the Crankshaft Position sensor for both spark and fueling. You can expect a certain amount of acceleration/deceleration between each firing stroke, but if the crankshaft speed changes are greater than an expected amount, the PCM interprets this as a misfire. The PCM times the interval between each pulse and compares each new time interval with the previous one in order to determine when an excessive change in crankshaft speed has occurred. The PCM provides a 12 volt power supply to the CKP sensor as well as a ground and a signal circuit.Ī misfire causes a change in crankshaft speed. The reluctor wheel is inside the engine immediately in front of the rear main bearing. The Crankshaft Position sensor works in conjunction with a 24X reluctor wheel on the crankshaft. The Crankshaft Position sensor is mounted through the side of the engine block at the rear of Bank 2 behind the starter assembly.