Abstract

A hydraulically operated camshaft phasing mechanism has two lock pins. One of the lock pins engages at an intermediate position and an end lock pin engages near one of the stops at the end of the phaser range of authority. At least one of the locking pins, preferably the end lock pin, when the vane is at an end stop position, is engaged by oil pressure and spring loaded to release when the oil pressure side of the end lock pin is vented.