Activated charcoal filter (cars with the letter designation of the engine BAA and BMX)

Operating principle

Above the surface of fuel in the tank depending on the pressure and the ambient temperature are formed to a greater or lesser degree of fuel vapor.

System Activated charcoal filter prevents ingress data hydrocarbon vapors into the atmosphere.

Fuel vapors come from the highest point of the fuel tank (for filler) through the expansion tank in the activated charcoal filter.

The activated carbon absorbs the gases such as sponge.

During the movement of the active lambda control (engine warm) solenoid valve 1 activated charcoal canister N80 and solenoid valve 2 Activated charcoal filter N115 is controlled depending on the load and speed of the engine control unit. Opening depends on the incoming signals.

During the cleaning process (regeneration of activated carbon) by vacuum in the intake manifold through the vent pipe absorber absorbed fresh air. Contained in the activated carbon at a particular time a pair of fuel and clean air are metered, and then burned in the engine.

In the absence of power supply (eg. A gap in a circuit) of the absorber solenoid valves are closed. In this case, the absorber is not emptied.

Description of the principles of the system diagnostics tightness

Absorber system (including the fuel tank) equipped with a leak diagnostic system which detects leaks in the system.

Diagnosis is based on the principle of overpressure and must point of leaks having a diameter greater than 1 mm.

At the time of diagnosis through the fuel system diagnostic pump V144 system absorber is pressurized about 30 mbar. When a predetermined pressure is reached, the pump stops. If the pressure falls below a certain value, the pump is activated again. Self-diagnostic system monitors the frequency of switching on the pump and at too short intervals stores the fault error.