Crankshaft Position Sensor: Description and Operation

Hall Generator:

Standard Wave Pattern:

PURPOSE
The Crankshaft Position and the Camshaft Position Sensors create square wave signals used by the ECM as reference for ignition and fuel injection timing.

OPERATION
- The crankshaft position sensor detects the crank angle (piston position) of each cylinder. converts it to a pulse signal and inputs it to the engine control module. The engine control module computes the engine speed and the intake air amount for one stroke and outputs the injector drive signal and injection command signal based on this signal.
- Power to the camshaft position sensor is supplied from the MFI relay and the ground is located in the body.
- 5 volts is applied from the engine control module to the camshaft position sensor output terminal and the camshaft position sensor generates a pulse signal as it switches from OPEN to SHORT (power transistor inside the sensor switches ON/OFF) between the output terminal and the ground.

CONSTRUCTION
Both sensors are incorporated into one unit consisting of a semiconductor wafer element and a permanent magnet. A rotating shutter called the trigger wheel acts as a switching device to produce the Hall signal.