Signal Waveform And Data
The oil control valve is commanded by a pulse-width-modulated signal from the engine control unit. A duty cycle of zero commands the cam phaser to its default position. A duty cycle of 100% commands the phaser to its maximum phased position. When the phaser must be controlled to an intermediate position, the duty cycle is maintained in the region of the `hold position'. This is a medium duty cycle, usually between 35% and 65%, depending on temperature and voltage conditions.