Crankshaft Position Sensor: Description and Operation

Crankshaft Sensor

The crankshaft sensor is a primary input to the EMS2000. It is used to determine the speed and position of the engine crankshaft. The sensor is a Hall Effect device. This provides a digital electrical signal that is created as the reluctor ring targets pass the sensor. The reluctor ring tooth pattern consists of 58 targets and a space of two missing teeth grouped together (6� tooth intervals). As the engine rotates the sensor output enables the EMS2000 to determine the crankshaft position and speed.
The missing teeth are essential for correct engine operation. They are used by the EMS2000 as an angular reference point. This information is used in combination with information from the camshaft sensor to determine the correct timing for the spark and fuel delivery.

Diagnosis
During cranking the digital signal produced by the sensor is sent to the EMS2000. The EMS2000 expects to receive a signal of 58 targets and two missing targets. If this signal is received the EMS2000 will synchronize itself to the engine. (The EMS2000 knows crankshaft position.) In the event a faulty or improper signal is received the EMS2000 will not begin or allow injection or ignition.
There is no crankshaft back up facility on the EMS2000 because the camshaft sensor target only produces one pulse per revolution.


Crankshaft sensor

Function
The signal from the crankshaft sensor is required by the engine control module to establish the rotation speed and position of the crankshaft. The Hall sensor determines a digital signal from a sensor wheel. This sensor wheel is located on the crankshaft and it has a gap in its tooth profile. The teeth are arranged at gaps of 6� around the sensor wheel. The sensor generates an electrical signal when the engine turns. This signal is routed to the engine control module.

The gap is important for correct engine operation, as it is used for the synchronization of the engine control module with the motor. For the synchronization, the position of the gap on the sensor wheel must be stored in the engine control module. The synchronization is required to establish the crankshaft position and the engine speed. This information is mainly required to calculate the firing point and the fuel delivery volume. The synchronization takes place during the starting process.

Failure
If the synchronization is not successfully concluded, the flow of fuel is interrupted.



Function
The signal from the crankshaft sensor is required by the engine control module to establish the rotation speed and position of the crankshaft. The Hall sensor determines a digital signal from a sensor wheel. This sensor wheel is located on the crankshaft and it has a gap in its tooth profile. The teeth are arranged at gaps of 6� around the sensor wheel. The sensor generates an electrical signal when the engine turns. This signal is routed to the engine control module.

The gap is important for correct engine operation, as it is used for the synchronization of the engine control module with the motor. For the synchronization, the position of the gap on the sensor wheel must be stored in the engine control module. The synchronization is required to establish the crankshaft position and the engine speed. This information is mainly required to calculate the firing point and the fuel delivery volume. The synchronization takes place during the starting process.

Failure
If the synchronization is not successfully concluded, the flow of fuel is interrupted.