Prowler V6-3.5L VIN G (1999)
Camshaft Position Sensor: Description and Operation
Camshaft Position Sensor 1999
Camshaft Sprocket - Typical
CAMSHAFT POSITION SENSOR
The camshaft position sensor provides cylinder identification to the Powertrain Control Module (PCM). The sensor generates pulses as groups of
notches on the camshaft sprocket pass underneath it. The PCM keeps track of crankshaft rotation and identifies each cylinder by the pulses
generated by the notches on the camshaft sprocket. Four crankshaft pulses follow each group of camshaft pulses.
When the PCM receives two camshaft pulses followed by the long flat spot on the camshaft sprocket, it knows that the crankshaft timing marks for
cylinder one are next (on driveplate). When the PCM receives one camshaft pulse after the long flat spot on the sprocket, cylinder number two
crankshaft timing marks are next. After 3 camshaft pulses, the PCM knows cylinder four crankshaft timing marks follow. One camshaft pulse after
the three pulses indicates cylinder five. The two camshaft pulses after cylinder 5 signals cylinder six. The PCM can synchronize on cylinders 1 or
4.
When metal aligns with the sensor, voltage goes low (less than 0.3 volts). When a notch aligns with the sensor, voltage spikes high (5.0 volts). As
a group of notches pass under the sensor, the voltage switches from low (metal) to high (notch) then back to low. The number of notches determine
the amount of pulses. If available, an oscilloscope can display the square wave patterns of each timing event.
Top dead center (TDC) does not occur when notches on the camshaft sprocket pass below the cylinder. TDC occurs after the camshaft pulse (or
pulses) and after the 4 crankshaft pulses associated with the particular cylinder. The arrows and cylinder call outs on which cylinder the flat spot
and notches identify, they do not indicate TDC position.
