Tank vent shutoff valve
The tank vent shutoff valve is necessary for a diagnosis of the tank ventilation system.
The N55 engine has two purge air lines from the tank vent valve to the air intake duct:
- from the fuel tank ventilation valve via the suction jet pump valve before the twin-scroll exhaust turbocharger
- from the tank vent valve to the throttle body.
Both lines must therefore be checked for throughflow in the event of malfunctions.
When the first purge air line is being checked, the second is closed using the shutoff valve.
The amount of fuel vapor drawn in by the combustion engine from the activated carbon canister must be adapted to each operating condition of the engine. The fuel tank ventilation shutoff valve is activated by the Digital Engine Electronics (DME).
| Index | Explanation |
|---|---|
| 1 | two-pin plug connection |
| 2 | Tank vent shutoff valve |
| 3 | Connection to throttle body |
| 4 | Connection to suction jet pump |
| 5 | Activated carbon filter connection |
| 6 | two-pin plug connection |
| 7 | Tank vent valve |