Diagnosing Fuel Fill Problems
Symptoms for a blocked inlet path will include:
- Inability to dispense fuel at anything above "trickle" rate, if that. Fuel evident at fill head.
- Nozzle will shut-off virtually immediately, since no volume of fuel can be dispensed.
- Suspect a stuck inlet check valve. Check for operation with siphon hose.
Symptoms for a blocked/restricted vent path include:
- Pre-mature shut-offs of fill nozzle at medium to high flow rates.
- Nozzle will shut-off after dispensing only 0.76 - 0.14 L (0.2 - 0.3 gallons - may be less with higher temperatures and/or higher RVP fuels). After a few second wait, this process can be repeated.
- Connect Scan tool and check for DTC P0446.
- Verify vent path:
- Ignition On, Engine Off.
- Using Scan tool, monitor FUEL TANK PRESS. SENSOR.
- Normal fuel tank pressure sensor signal voltage with no pressure or vacuum should read between 2.3 - 2.8 volts.
- Check vent path from EVAP vent solenoid backwards to isolate problem component (vent solenoid, vent pipe/hose, canister, Fill Limit Vent Valve (FLVV), etc.).