Camshaft Position Sensor: Description and Operation

Cam And Crankshaft Sensor Circuit Diagram:

Front Top On Engine:

PURPOSE
The camshaft sensor produces a signal indicating the beginning of the intake stroke for #1 cylinder. The signal is used to determine injection timing. Injection begins with #1 cylinder on the intake stroke and then follows the firing order. If this signal is not present, injection will not begin and the engine will not start. If this occurs, a code 17 will set.


LOCATION AND OPERATION
The camshaft sensor is a hall-effect sensor installed on the top front of the engine, above the front of the camshaft. The tip of the sensor comes very near a reluctor "pole" piece, cast as part of the camshaft. When this pole piece passes the sensor tip, the disturbance in the sensors magnetic field turns the hall-effect switch "OFF" and "ON" again, producing a signal that the computer can read.