there is a series of holes drilled in the snout of the cam through the front bearing and leading to the cam phaser, one hole advances the cam and one retards it, there is one solenoid valve in the peak of the triangle of the block and a single valve that I think is cycled to send flow to the advance or retard holes in the phaser and maintain a certain advance/retard based on RPM, Load and probably other variables. The cam sensor detects the cam position and how many degrees advanced or retarded it is in relation to the crank and makes adjustment to oil flow based on those two sensors. The oil flow there only affects oil to the cam phaser and not anything else so you could just leave the solenoid unplugged to plug the hole and not worry about where oil is being affected elsewhere in the engine, it will also let oil reach the cam bearing so it dont burn up.

You can take apart the phaser and block it from moving very easily, you can also adjust cam timing by blocking it in a more or less retarded/advanced position based on how much "shims" you use on either side of the vanes and thereby degree it in without buying an adjustable timing set.