A disclosed lubrication system for turbofan engine includes a primary lubricant circuit, a primary pump driving lubricant through the primary circuit, an auxiliary lubricant circuit in communication with the primary lubricant circuit and an auxiliary lubricant pump driving lubricant through the auxiliary lubricant circuit. A first valve downstream of an outlet of auxiliary lubricant pump separates the auxiliary lubricant circuit from the primary lubricant circuit. A sensor is disposed within the auxiliary lubricant circuit for sensing pressure within the auxiliary lubricant circuit separate from a pressure within the primary lubricant circuit.