Fuel Evaporative (EVAP)
WARNING: This page is about a different car, the 1996 Volvo 850. However, it is still accessible from the selected car via links, so may be relevant.
If circuit or component is faulty, a trouble code should set. See appropriate articles; For Motronic 4.3L see TESTS W/CODES - 4.3L, For Motronic 4.4L see TESTS W/CODES - 4.4L.