P0441

P0441

Diagnosis information - DME (DFI)

Fuel tank ventilation system

NOTE: Diagnosis is carried out on the tank vent by evaluating the lambda controller (or the throttle valve adjusting unit or the retraction of the ignition timing angle) as a result of rich/lean fluctuations (or idle controller changes) when opening or closing the tank vent.

Diagnostic conditions
- Vehicle voltage more than 9 V
- Time after engine starts more than 2 minutes
- Engine idling more than 20 seconds
- Engine temperature more than 60°C (140 °F)
- Ambient air pressure more than 730 hpa
- Vehicle is stationary
- No additional load due to air conditioning, steering, etc.
- All oxygen sensors ready for operation
- No oxygen sensor fault stored
- No tank vent driver fault stored

Possible fault causes
- Tank vent faulty (remains stuck in an open or closed position)
- Tank vent installed back to front
- 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)