Audi A4, S4

since 2000 of release

Repair and car operation

Systems of decrease in toxicity of release - the general information

Scheme of connection of vacuum lines. Engine of 1.8 l

Cхема of connection of vacuum lines. V6 engine

Petrol models

System of ventilation of a case

For elimination of leakages of not burned down hydrocarbons in the atmosphere the engine is completely pressurized. Gases and pairs of oil which are forming in a case, via the mesh filter get to the inlet pipeline and burn down in cylinders together with fuel.

Gases are removed from a case at the expense of a pressure difference in a case and the inlet pipeline (pressure in a case is higher).

Catalytic converter

For decrease in number of harmful emissions the three-functional catalytic converter is built in the atmosphere on all petrol models in system of release. The control system of injection of fuel has feedback in which it is included a lambda probe. This sensor established in system of release, constantly informs the control unit on composition of the fulfilled gases. Depending on the received data, the control unit corrects quality of the mix submitted to chambers of combustion and, thus, optimizes fuel combustion.

In a lambda probe the heating element which is switched on by the control unit through the special relay is built in. The working surface a lambda probe is sensitive to change of the content of oxygen in gases. Depending on concentration of oxygen, the sensor sends signals of different tension. If the mix переобогащена - the content of oxygen in the fulfilled gases very low, the sensor submits signals with a low voltage. Tension increases in process of pauperization of a mix and increase in the content of oxygen in gases. Most effectively the converter works at optimum quality of gas mixture (14.7 parts of air for 1 part of fuel). At optimum concentration of oxygen in the fulfilled gases there is a jump in tension on the sensor. This jump is a reference point for the control unit at correction of quality of a mix.

It is established on two sensors. One - before, and the second — after the converter. It reaches more exact tracking of composition of the fulfilled gases.

System of a retsirkulyatsiya of the fulfilled gases

The system of a retsirkulyatsiya of the fulfilled gases allows to reduce quantity _{of NOx} in the fulfilled gases. For this purpose the small part of the fulfilled gases moves in the inlet pipeline via the special valve. The valve of system of a retsirkulyatsiya copes the control unit.

Catching system паров fuels

Lines of system of catching паров fuels. Engine of 1.8 l

1 — the Vacuum control valve 2 — the Valve of management of a purge of an adsorber of EVAP 3 — the Final pipeline from the valve of management of a purge of an adsorber of EVAP 4 — the Final pipeline from the gravitational valve 5 — an EVAP system Adsorber 6 — To the pump of definition of leaks 7 — the Casing of the air filter	8 — the Pump of definition of leaks 9 Vacuum hose of an inlet air line to the pump of definition of leaks 10 — the Vacuum chamber 11 — the Control valve 12 — the Vacuum distributor "T" 13 — the Module of management of the butterfly valve valve

Lines of system of catching паров fuels. V6 engine

For decrease in emission in the atmosphere of not burned down hydrocarbons on all petrol models the system of catching of fuel is established. The refueling mouth of a fuel tank is tightly closed by a cover, under a fuel tank the coal adsorber is established. In it pairs of fuel which are forming in a tank during parking of the car gather, and are stored there until on a signal of the control unit the adsorber purge will not begin. Then pairs of fuel start to move via the purge valve in the inlet pipeline, there they mix up with a working mix and further burn down usually in combustion chambers.

For ensuring normal operation of the engine on single turns and during warming up the control unit holds the valve the closed. Thus hit of not burned down fuel in the converter (is prevented at the raised turns of idling a mix переобогащена). After engine warming up the valve starts to open and be closed, submitting pairs of fuel to an inlet path.

Diesel models

The control system of the engine functions so that to receive the maximum return from the engine at the minimum fuel consumption and toxicity of the fulfilled gases. For additional decrease in toxicity of gases on the car some additional systems are established. System of ventilation of a case of a snizhayetutechka of gases in the atmosphere from system of greasing of the engine. The catalytic converter reduces toxicity of the fulfilled gases. The system of a retsirkulyatsiya of the fulfilled gases is established.

System of operated ventilation of a case

For elimination of leakages of not burned down hydrocarbons in the atmosphere the engine is completely pressurized. Gases and pairs of oil which are forming in a case, via the mesh filter get to the inlet pipeline and burn down in cylinders together with fuel.

Gases are removed from a case at the expense of a pressure difference in a case and the inlet pipeline (pressure in a case is higher). On all diesel models the ventilation valve is established. It is on a cover of a head of the block and operates a stream of gases from a case.

System of a retsirkulyatsiya of the fulfilled gases

On all diesel models the system of a retsirkulyatsiya of the fulfilled gases is also established. This system allows to reduce quantity _{of NO x} in the fulfilled gases. For this purpose the small part of the fulfilled gases moves in the inlet pipeline via the special valve. The valve of system of a retsirkulyatsiya is supervised by the control unit.