Variable Valve Timing Actuator: Description and Operation

Camshaft Actuator System Description






Camshaft Position (CMP) Actuator System

The camshaft position (CMP) actuator system is used for a variety of engine performance enhancements. These enhancements include lower emission output through exhaust gas recirculation (EGR) control, a wider engine torque range, improved gas millage, and improved engine idle stability. The CMP actuator system accomplishes this by controlling the amount of valve overlap.


CMP Actuator System Operation

The camshaft position (CMP) actuator system is controlled by the powertrain control module (PCM). The PCM sends a signal to a CMP actuator solenoid in order to control the amount of engine oil flow to a Cam Actuator passage. There are 2 different passages for oil to flow through, a passage for cam advance and a passage for cam retard. The Cam Actuator is attached to a 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 and engine oil level can have an adverse affect on Cam Actuator performance.