Here is the deal. if you clear the code(turn off the light) and upon restarting it ,before driving it, the light comes back on. you have a sensor problem, if the light doesnt come on till after you have driven it , it could be either part but is likely the solonoid. this code has 2 logics, one if it doesent see a signal while the car is running, or if it doesnt see a logical signal while under part thorttle acceleration. Meaning the ecm is watching degrees of cam advance as compared to solonoid duty cycle, if the ecm is increasing duty cycle by say 50 to 60% and the cam degree does not advance and is typically 7 degrees behind its opposing bank for a constant 20 seconds it thinks there is a problem, the computer does not have the ability to distiguish which part is failing so it throws the one code, this is where consultII comes in handy, I am able to watch both sensors in degrees and watch both solonoids in % of duty cycle, If my degrees are registering very low but registering non the less and the duty cycle on the affected bank is substantially higher then the opposing bank the sensor is functioning but the solonoid is not allowing enough oil through to opperate the VTC. therefore the solonoid either has a restricted port or a week electromagnetic field causeing it not to open fully. Now in the other case if the degrees on the cam lock at 0 or 120 degrees it is the sensor, the typical range for the degrees under normal driving conditions is between 7 and 16 degrees.
There you go guys, hope this sheds some light on what your dealing with.

Scott