Small EVAP Leak Test

TEST DESCRIPTION

The control module performs the Small EVAP Leak Test in order to detect a small leak in the following components of the EVAP system:

^ The fuel filler cap.
^ The fuel filler neck.
^ The EVAP canister.
^ The EVAP vent valve.
^ The EVAP vapor pipes and hoses.

NOTE: The Small EVAP Leak Test does not test the EVAP purge solenoid for leaks.

In order to run the Small EVAP Leak Test the control module performs the following:

1. Turn the EVAP purge valve OFF (closed).
2. Following the passed Weak Vacuum Test and while the EVAP vent valve is still turned ON (closed), run the Small EVAP Leak Test.
3. Monitor the fuel tank pressure sensor signal.

The control module monitors the vacuum trapped in the system. If the control module detects a excessive decrease in the vacuum that is trapped in the system a DTC P0442 is set.