System Description

The DTC P0441 Evaporative Emission (EVAP) System No Flow During Purge diagnostic monitors the changes in the vacuum pressure in the fuel tank. The diagnostic strategy for the EVAP system uses a vacuum pump to test for system leaks, after the engine is OFF. A unique fuel tank, EVAP canister, and EVAP vacuum leak pump work together to provide enhanced system diagnosis. The vacuum leak pump, the fuel tank pressure (FTP) sensor and the EVAP canister vent valve are all integral parts of one assembly. The assembly is attached directly to the EVAP canister, located near the fuel tank.

After the vehicle has sat with the engine OFF for about 5 hours, a comprehensive diagnostic is enabled with no operator input necessary. The complete test can take up to 15 minutes to run, with leak detection comprising the largest portion of the test. If the powertrain control module (PCM) detects the vacuum level was not achieved, DTC P0441 will set. For more detailed information on the EVAP system components and diagnostic strategy, refer to Evaporative Emission Control System Description .