1. A compressor comprising: first and second movable members operative to pressurize fluid; a suction pressure zone in communication with said first and second movable members; a discharge pressure zone in communication with said first and second movable members; a force-applying structure operable to modulate a capacity of the compressor; a first fluid passage extending between said force applying structure and said suction pressure zone; a valve member disposed within said first fluid passage, said valve member operable to open and close said first fluid passage; and a first temperature sensor for sensing a first fluid temperature within said first fluid passage and operatively connected to said valve member for determining an operational status.