A diagnostic system for a crankcase ventilation system of a boosted engine includes a pressure sensor (i) disposed in-line along a make-up air (MUA) hose of the crankcase ventilation system and (ii) configured to measure a pressure in the MUA hose, the MUA hose connecting an induction system of the engine to a crankcase of the engine. The diagnostic system also includes a controller configured to: detect a mild acceleration operating condition of the engine; and in response to detecting the mild acceleration operating condition: obtain a plurality of pressure samples based on the measured pressure by the pressure sensor, compare the plurality of pressure samples to a fault threshold indicative of a disconnected MUA hose, and based on the comparing, generate a fault signal indicative of a disconnected MUA hose.