Purge Flow Sensor: Description and Operation

DESCRIPTION
The system checks for conditions that cause the EVAP system to purge continuously by commanding the EVAP vent solenoid on and the EVAP purge solenoid off (EVAP vent solenoid CLOSED, EVAP purge PWM 0%). If fuel tank pressure level increases during the test, a continuous purge flow condition is indicated. This can be caused by the following conditions:
^ EVAP purge solenoid leaking
^ EVAP purge and engine vacuum source lines switched at the EVAP purge solenoid
^ EVAP purge solenoid driver circuit grounded If any of these conditions are present, DTC P1441 will set.

NOTE: Refer to the DTC charts for further diagnostic procedures regarding the EVAP system.