Spool Valve and Oil Pressure Switch
The spool valve assembly, or oil flow control module, is mounted to the front right of the engine block at the oil pump housing. The module consists of an oil filter (410), solenoid (416), spool valve (414) and spring (413). The module controls oil flow between the oil pump and the synchronizing pistons of the intake rocker arms. When the solenoid is activated, the oil pressure pushes the spool valve downward. The spool valve then opens the oil passage, and hydraulic pressure is applied to the synchronizing pistons, thus activating the intake rocker arm control system. The oil pressure sensor (437) is located on the housing by the solenoid valve and is in a normally closed position. The switch is used to detect oil pressure and to activate the intake rocker arm control system. The PCM provides 5 volts to the switch, the switch opens through the body, the solenoid is energized, and oil pressure applied.