A crankshaft position (CKP) sensor is mounted on the front of transmission case adjacent to the flywheel. The CKP sensor is a hall-effect type sensor that generates voltage using a sensor and a target wheel mounted on the crankshaft. There are 58 slots and one longer slot on the target wheel. When the slot in the wheel aligns with the sensor, the sensor voltage output is low (approx. 0V). and it is high (approx.5V) when a slot is not aligned with the sensor. During one crankshaft rotation there are 58 rectangular signals and one longer signal. The ECM calculates the frequency to compute engine rpm to determine the injection duration and ignition timing. Using the signal differences caused by the longer slot, ECM identifies which cylinder is on top dead center.