Purge Valve Leak Test

Purge Valve Leak Test

It 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 P0496 will set.