Diagnostic Aids
WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
Make a visual inspection for a large leak of EVAP system. Use EVAP pressure/purge diagnostic cart and ultrasonic lead detector to locate large leak.
Possible causes of a large leak:
- Fuel cap missing, incorrectly installed or leading.
- EVAP vent solenoid stuck open.
- EVAP purge solenoid stuck closed or blocked.
- EVAP vent hose loose or damaged.
- EVAP canister leaking.
- Fuel sender assembly O-ring leaking.
- Fuel tank or filler neck leaking.
A very large leak, such as a missing fuel cap, may be difficult to pick up with the ultrasonic leak detector. For potential leak areas, see Fig 1 .