For 1990-2009 cars

Problems associated with refueling the vehicle such as premature shutoffs of the fill nozzle or inability to dispense fuel at a high rate are related to 2 areas:

• | A blocked inlet (i.e., the fill pipe)

| OR

• | The primary vent path is blocked or severely restricted.

Redesign of the fuel fill inlet and vent path was done as a result of Onboard Refueling and Vapor Recovery (ORVR) requirements.

### Diagnostic Aids

Symptoms of a blocked inlet path will include:

• | An inability to dispense fuel at anything above a trickle rate, if that.

| Fuel evident at fill head.

• | Nozzle shutting off virtually immediately, since no volume of fuel can be dispensed.

| Suspect a stuck inlet check valve. Check for operation with siphon hose.

Symptoms of a blocked/restricted vent path include:

• | A premature shutoff of fill nozzle at medium to high flow rates.

• | Nozzle shutting off after dispensing only 0.8-1.1 L (0.2-0.3 gallons). May be less with higher temperatures and/or higher RVP fuels. After a few seconds of waiting, this process can be repeated.

• | Connect the scan tool and look for DTCs P0446 or P0449.

• | Verify vent path during refueling. Connect the scan tool and go into enhanced evaporative emission (EVAP) tests to control vent solenoid and read fuel tank pressure sensor.

- | Normal sensor voltage is 1.4-1.6 volts. It will decrease with rising tank pressure (during refueling) and during refueling will stabilize just below 1 volt.

- | If voltage drops rapidly below this value towards 0.2-0.3 volts during refueling, this is indication that the major vent path is blocked.

- | Check vent path from EVAP vent solenoid backwards to isolate problem component (vent solenoid, vent pipe/hose, canister, fill limit vent valve (FLVV), etc.)