Phase Angle Retards

In response to a retard signal from the ECM, the oil flow control solenoid valve moves its spool such that hydraulic pressure is applied to the retard chamber in the camshaft sprocket. The sprocket is then turned in the direction in which its phase angle retards relative to the camshaft.

Fig 1: Identifying Variable Valve Timing Controller, Vane, ECM And Oil Flow Control Solenoid Valve (Phase Angle Retards)

Courtesy of SUBARU OF AMERICA, INC.