RAM 3500 Van V8-360 5.9L Magnum (1995)
Camshaft Position Sensor: Description and Operation
PURPOSE
The signal from the camshaft position sensor combined with the input signal from the Crankshaft Position (CKP) Sensor, are what the Powertrain
Control Module (PCM) uses to differentiate between fuel and spark events. Input is also used to properly synchronize fuel injection.
OPERATION
The PCM identifies cylinders by monitoring signals from the crankshaft and camshaft position sensors. The PCM uses these input signals to
determine fuel injector synchronization.
The camshaft position sensor contains a hall effect device called a sync signal generator, which generates the fuel sync signal. The sync signal
generator detects a rotating pulse ring (shutter) on the distributor shaft. The pulse ring rotates 180 degrees through the sync signal generator. This
signal is used in conjunction with the crankshaft position sensor to differentiate between fuel synchronization and spark events. It is also used to
synchronize the fuel injectors with their respective cylinders.
When the leading edge of the pulse ring (shutter) enters the sync signal generator, the interruption of the magnetic field causes the voltage to
switch high, resulting in a sync signal of approximately 5 volts.
When the trailing edge of the pulse ring (shutter) leaves the sync signal generator, the change of the magnetic field causes the sync signal to switch
low to 0 volts.
If PCM does not sense input from cam position sensor, PCM will deactivate the automatic shutdown relay and fuel pump relay, interrupting
voltage to fuel pump, fuel injectors, and ignition coil, causing a no start condition.
