P0441
P0441Fuel tank ventilation system above limit value/below limit value
Diagnostic conditions - V8
- Battery positive voltage between 10 V and 16 V
- Time after engine starts > 11 minutes and 30 seconds
- Idle speed
- All oxygen sensors ready for operation
- No oxygen sensor fault stored
- No tank vent driver fault stored
Diagnostic conditions - V6
- Battery positive voltage between 10 V and 16 V
- Engine temperature > 60 °C
- Ambient temperature > 4.5 °C
- Altitude factor > 0.72
- Time after engine starts > 10 minutes and 10 seconds
- Idle speed
- All oxygen sensors ready for operation
There must not be any stored faults for the following systems:
- Oxygen sensors
- Tank valve driver
- Throttle adjusting unit
- Hot film mass air flow meter
- Coolant temperature sensor
- Idle speed control
- Vehicle speed
Possible cause of fault
- Tank vent faulty (remains stuck in an open or closed position)
- Tank vent installed the wrong way round
- Leak in scavenging lines between tank vent and positive crankcase ventilation (in the Turbo via a T-piece also on the intake side of the turbocharger)
- Scavenging lines between tank vent and positive crankcase ventilation trapped or blocked (in the Turbo via a T-piece also on the intake side of the turbocharger)
Affected terminals
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Diagnosis/troubleshooting
NOTE:
- The diagnostic conditions can also be 'enforced' by the "tank vent" short test using the 9588 Porsche System Tester II
- The tank valve is located on the left in the direction of travel beside the throttle adjusting unit
- In the Turbo, the tank vent wire leads to the positive crankcase ventilation flange and to a hose connection on the intake side of the turbocharger.
- The diagnosis is carried out on the tank vent by evaluating the oxygen sensor (or the throttle adjusting unit or the retraction of the ignition timing angle) as a result of rich/lean fluctuations (or changes in speed) when opening or closing the tank valve.
Fuel tank ventilation system above limit value
Fuel tank ventilation system below limit value
