Audi Workshop Service and Repair Manuals > A4 Mk3 > Power unit | 6-cylinder TDI engine (2.7 ltr.; 3.0 ltr. 4-valve common rail), mechanics | Exhaust system | Reducing agent metering system - vehicles with SCR catalytic converter

Draining active tank for reducing agent

Special tools and workshop equipment required

t	Engine bung set -VAS 6122-

Drip tray

Procedure

Observe safety precautions → Chapter.

Observe rules for cleanliness → Chapter.

–	Open tank flap.

–	Unscrew filler cap -2- from filler neck for reducing agent.

Note

Disregard -item 1-.

–	Remove bolt and nuts -arrows- and detach cover for active tank.

WARNING

Reducing agent can cause skin irritation.

t	Avoid contact with the skin and eyes. Wear gloves and safety goggles.

t	If your skin has come into contact with reducing agent, rinse it off with soap and water.

t	If reducing agent gets into your eyes, rinse them out with water for several minutes.

t	Do not breathe in or swallow reducing agent.

t	If you have swallowed reducing agent, rinse your mouth, drink lots of water and consult a paramedic or doctor immediately.

–	Place drip tray underneath.

Note

Hold a clean cloth under the separating point to catch escaping reducing agent.

–	Press release catches → Fig. and disconnect return line -1- from reservoir.

–	Attach auxiliary hose -2- to connection -arrow- on reservoir and drain off reducing agent into drip tray.

–	Seal off open pipes/lines and connections with clean plugs from engine bung set -VAS 6122-.

After re-filling, the following step must be carried out:

–	Adapt learnt value after draining reducing agent or renewing components → Chapter.

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