Circuit Description

Evaporative (EVAP) emission system includes following components: fuel tank, EVAP vent solenoid, fuel tank pressure sensor, fuel pipes and hoses, vapor lines, fuel cap, EVAP emission canister, purge lines, and EVAP purge solenoid.

PCM will test the EVAP system for large and small leaks (DTC P0440 and P0442), excess vacuum (P0446), purge flow during non-commanded conditions (P1441), fuel pressure sensor and fuel level faults (P0452, P0453, P0462 and P0463), and EVAP purge and vent valve faults (P0443 and P0449).

DTC will set when EVAP system exceeds a vacuum threshold or if there is too much system vacuum present at the start of this test.