6 Check ventilation lines.
Check whether ventilation lines are:
- cracked
- broken
- interrupted
7 Check EVAP canister purge valve.
1. Remove front right-hand wheel housing liner.
2. Clean EVAP canister in the vicinity of the ventilation lines.
3. Detach the ventilation line to the EVAP canister purge valve at the EVAP canister (connection with protective cap).
4. With special tool 9160/1, generate a vacuum of 200 mbar (0.2 bar).
If no vacuum can be built up, replace the EVAP canister purge valve.
P0456
P0456
Fuel Tank Ventilation System (Minor leak) - Below Limit
Diagnosis conditions
- Oxygen sensing system active
- Engine running
- Vehicle speed = 0 km/h
- Intake air temperature between 5 锟斤拷C and 60 锟斤拷C
- Altitude correction factor greater than 0.75
- Battery positive voltage greater than 11 V
- Engine load less than 30%
- EVAP canister burden less than 3
- Time elapsed after engine start-up greater than 990 seconds or mixture adaptation completed
- No other faults in memory
Possible fault cause
- Tank cap seal
- One or several leaks in fuel tank ventilation system
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.
- The EVAP canister purge valve is very sensitive to contamination. If the lines to the EVAP canister have to be detached, the outside of the
canister must be cleaned beforehand.