System Description

WARNING: This page is about a different variant/trim than selected.

The Evaporative Emission (EVAP) System is used to store fuel vapors to reduce the amount of unburned fuel from escaping into the atmosphere. The EVAP canister purge solenoid valve is pulse width modulated (PWM) and is used to control the flow of fuel vapors from the EVAP canister to the intake manifold. The EVAP canister purge solenoid valve is commanded ON, PWM, whenever the EVAP system is in purge mode. Fuel vapors can be purged at anytime the engine control module (ECM) is in Closed Loop and the vehicle is not in a decel. The ECM controls the EVAP canister purge solenoid valve by controlling an internal driver that pulls the solenoid valve circuit to ground. During one part of the EVAP diagnostic system test, the ECM will close the EVAP canister purge solenoid valve and the EVAP canister vent solenoid valve. DTC P0496 sets when the fuel tank pressure (FTP) sensor indicates that the pressure is lower than atmospheric, vacuum, indicating the EVAP canister purge solenoid valve is stuck open.