Note. For circuit reference, see ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. For component locations, see COMPONENT LOCATIONS . For connector identification, see CONNECTOR IDENTIFICATION .
Circuit Description
The DTC P0441 Evaporative Emission (EVAP) System No Flow During Purge diagnostic monitors changes in vacuum pressure in the fuel tank. Powertrain Control Module (PCM) will command EVAP vent valve ON (closed), and vacuum pressure switching valve ON (open), with engine running. This allows engine vacuum into entire EVAP system. PCM continues to operate purge valve until vacuum has reached a specified limit, at which time the PCM commands purge valve OFF (closed). If PCM detects vacuum level was not achieved, or vacuum level increased beyond the specified limit, a DTC P0441 will set.
Conditions for Running the DTC
- Barometric (BARO) pressure is more than 75 kPa.
- Fuel level is 25 and 75 percent.
- ECT sensor and Intake Air Temperature (IAT) sensor are near the same temperature at engine start.
- ECT sensor is at least 74°C (165°F) after engine warm up.
Conditions for Setting the DTC
The pressure indicated in EVAP canister and fuel tank does not drop when EVAP canister purge valve is ON. Or, pressure indicated in EVAP canister remains very low when compared to atmospheric pressure when EVAP canister purge solenoid valve is OFF.
Action Taken When the DTC Sets
- PCM illuminates Malfunction Indicator Light (MIL) after 2 consecutive ignition cycles in which the diagnostic runs with fault active.
- PCM records operating conditions at the time the diagnostic fails. This information is stored in freeze frame buffer.