CMP Actuator System Operation
WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, 2010 Chevrolet Silverado, and 2010 Chevrolet Cab & Chassis Silverado. 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 12-volt 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). Incorrect engine oil pressure (EOP), viscosity, temperature, engine oil level, or aftermarket engine oil additives can have an adverse affect on camshaft phaser performance.