A system for a vehicle includes a regeneration module and a disconnection indication module. The regeneration module indicates when a regeneration of a particulate filter is complete. The disconnection indication module receives a pressure difference across the particulate filter measured using delta pressure sensor. The delta pressure sensor generates the pressure difference based on first and second pressures upstream and downstream of the particulate filter applied to the delta pressure sensor using upstream and downstream pressure lines, respectively. In response to an indication that the regeneration of the particulate filter is complete, the disconnection indication module selectively indicates that the downstream pressure line is disconnected based on a comparison of the pressure difference and a predetermined pressure.