Variable Valve Control Device, Variable Valve Control System, and Method for Controlling Variable Valve Mechanism

In a variable valve control device, a variable valve control system and a method for controlling a variable valve mechanism according to the present invention, An ECM () transmits a phase detection value (RA) computed based on a crank angle signal (CRANK) and a cam angle signal (CAM) to a VTC control unit () via a communication network (), and VTC control unit () computes a phase detection value (RA) based on a motor angle signal (MAS), controls a variable valve timing mechanism () based on phase detection value (RA) in the transient state of an internal combustion engine, and controls variable valve timing mechanism () based on phase detection value (RA) in the steady state of the internal combustion engine.