DTC P1441: EVAP System Flow During Non-Purge: Description

DTC tests for undesired intake manifold vacuum flow to Evaporative (EVAP) emission system. Powertrain Control Module (PCM) seals EVAP system by commanding EVAP canister purge valve off and EVAP canister vent valve on. PCM monitors Fuel Tank Pressure (FTP) sensor to determine if a vacuum is being drawn on EVAP system. DTC sets when vacuum in EVAP system is more than a predetermined value within a predetermined time.

For the relationship between the on and off states, and the open or closed states of the EVAP canister purge and vent valves, see EVAP VALVE LOGIC  table under DTC P0440: EVAP SYSTEM.