95 - EVAP Canister Shutoff Valve (Function) - Below Limit

P0446

95 EVAP Canister Shutoff Valve (Function) - 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 degree C and 60 degree 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
- Purge air line blocked
- EVAP canister purge valve open
- Flow resistance of EVAP canister too high

Affected terminals

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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.

Work Instruction 1 - 2:

Figure:

Work Instruction 3: