E 150 V8-4.6L SOHC VIN W (2004)
The PCM calculates and determines the desired camshaft position. It will continually update the VCT solenoid duty cycle until desired positioning
is achieved. A difference between the desired and actual camshaft position represents a position error in the PCM's VCT control loop. The PCM
will disable the VCT and place the camshaft in a default position if a fault is detected. A related DTC will also be set when this fault is detected.
5. When the VCT solenoid is energized, engine oil is allowed to flow to the VCT actuator assembly which advances or retards the cam timing. One
half of the VCT actuator is coupled to the camshaft and the other half is connected to the timing chain. Oil chambers between the two halves
couple the camshaft to the timing chain. When the flow of oil is shifted from one side of the chamber to the other, the differential change in oil
pressure forces the camshaft to rotate in either a advance or retard position depending on the oil flow.