CMP Actuator System Operation
WARNING: This page is about a different car, the 2011 GMC Yukon, 2011 Chevrolet Tahoe, and 2011 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
The camshaft position (CMP) actuator system is controlled by the control module. The control module sends a pulse width modulated signal to a CMP actuator solenoid in order to control the amount of engine oil flow to a camshaft actuator passage. There are 2 different passages for oil to flow through, a passage for CAM advance and a passage for CAM retard. The camshaft actuator is attached to the front of the camshaft, and is hydraulically operated in order to change the angle of the camshaft relative to crankshaft position (CKP). Engine oil pressure (EOP), viscosity, temperature, engine oil level, and aftermarket engine oil additives can have an adverse affect on camshaft phaser performance.