Canister Purge Control Valve: Description and Operation

PURGE VALVE LEAK TEST
If the EVAP purge valve does not seal properly, fuel vapors could enter the engine at an undesired time causing driveability concerns. The control module tests for this by commanding the EVAP purge valve OFF closed and vent valve OFF OPEN, sealing the system, and monitoring the FTP for an increase in vacuum. If the control module detects that EVAP system vacuum increases above a calibrated value, DTC P1441 will set.

EVAP PURGE VALVE
The EVAP purge valve controls the flow of vapors from the EVAP system to the intake manifold. This normally closed valve is pulse width modulated by the control module to precisely control the flow of fuel vapor to the engine. The valve will also be opened during some portions of the EVAP testing, allowing engine vacuum to enter the EVAP system.