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

Evaporative Emission (EVAP) system is used to store fuel vapors as to reduce amount or unburned fuel from escaping into atmosphere. EVAP purge solenoid is used to control flow of fuel vapors from EVAP canister to intake manifold. EVAP purge solenoid is commanded on (PWM) whenever EVAP system is in purge mode. Fuel vapors can be purged at anytime PCM is in closed loop and vehicle is not in a decel. PCM controls EVAP purge solenoid by controlling an internal driver that pulls solenoid circuit to ground. EVAP purge solenoid circuit is monitored for low and high voltage faults. During one part of EVAP diagnostic system test, PCM will close EVAP purge solenoid and EVAP vent solenoid. DTC sets when fuel tank pressure sensor indicates that pressure is lower than atmospheric (vacuum) indicating EVAP purge solenoid is stuck open.