P0455

P0455

94 Fuel Tank Ventilation System (Major Leak) - Below Limit

Diagnosis conditions
- Oxygen sensing system active
- No secondary air diagnosis
- Engine running
- Vehicle speed = 0 km/h
- Intake air temperature between 4.5 °C and 60 °C
- Battery positive voltage greater than 11 V
- Engine load less than 30%
- EVAP canister burden less than 3
- Altitude correction factor greater than 0.75
- Time elapsed after engine start-up > 990 seconds or mixture adaptation completed
- No faults in memory

Possible fault cause
- Tank cap missing
- Tank cap seal
- Ventilation lines detached from EVAP canister
- Ventilation line detached from tank
- Ventilation line detached from fuel tank vent
- Break in ventilation lines

Diagnosis/troubleshooting

NOTE:
- Fuel tank ventilation diagnosis is initiated with the Porsche System Tester 2 in the "Short test" menu. This reduces the time elapsed after engine start-up to 30 seconds.
- A frozen EVAP canister shutoff valve can lead to this fault.







94 Fuel Tank Ventilation System (Major Leak) - Signal Implausible

Diagnosis conditions
- Oxygen sensing system active
- No secondary air diagnosis
- Engine running
- Vehicle speed = 0 km/h
- Intake air temperature between 4.5 °C and 60 °C
- Battery positive voltage greater than 11 V
- Engine load less than 30%
- EVAP canister burden less than 3
- Altitude correction factor greater than 0.75
- Time elapsed after engine start-up > 990 seconds or mixture adaptation completed
- No faults in memory

Possible fault cause
- Pressure sensor

Diagnosis/troubleshooting

NOTE: Fuel tank ventilation diagnosis is initiated with the Porsche System Tester 2 in the "Short test" menu. This reduces the time elapsed after engine start-up to 30 seconds.