Audi Workshop Service and Repair Manuals

Note:

• ◆ Since the fuel system does not have a return line, it must always be bled after any work on the fuel lines or fuel filter in order to avoid damage to the catalytic converter. The engine must not be started until the system has been bled.
• ◆ You can recognise the fuel system without return line by the fuel rail without return line. See: Dismantling and assembling fuel rail with injectors=>Page 24-26
• ◆ Observe rules for cleanliness =>Page: 24-4

• ‒ → Turn cut-off valve of special tool V.A.G 1318/21 in direction "-" onto stop.

• ‒ → Screw special tool V.A.G 1318/21 onto bleeder connection -2-.

• ‒ → Connect special tool V.A.G 1318/21 and diesel suction pump VAS 5226 by means of K-Jetronic pressure tester V.A.G 1318.

• ‒ → Open cut-off valve of special tool by turning valve in direction "+ ".
• ‒ Switch on ignition.

• The fuel pump runs for some seconds.
• Switch off ignition as soon as fuel comes out at diesel suction pump VAS 5226 free of bubbles. The fuel system is now bled.
• If the fuel pump does not start up or if the fuel does not come out at diesel suction pump VAS 5226 free of bubbles:

• ‒ Activate fuel pump via final control diagnosis=>Page 24-60

Notes:

• ◆ → Close cut-off valve by turning valve in direction "-" before unscrewing special tool.
• ◆ Fit protective cap on bleeder connection after bleeding is completed.

Final control diagnosis

Notes:

• ◆ The fuel pump runs automatically soon as the final control diagnosis is initiated.
• ◆ The final control diagnosis can only be performed with the ignition switched on and the engine not running.
• ◆ The final control diagnosis is terminated if the operator does not advance to the next step after 1 minute activation time, if the engine is started or if an engine speed pulse is detected.
• ◆ If the final control diagnosis is to be repeated, the engine must be started and the ignition switched off and then on again.

• ‒ Connect vehicle diagnostic, testing and information system VAS 5051 and select engine electronics control unit by entering address word "01".
  When doing this the ignition must be switched on.

→ Display on VAS 5051:

• ‒ Select diagnosis function "03 - Final control diagnosis" from the menu -1-
• ‒ Fuel pump runs for approx. 1 minute after pressing▸key.

• Switch off ignition as soon as fuel comes out at diesel suction pump VAS 5226. The fuel system is now bled.

Notes:

• ◆ → Turn cut-off valve in direction "-" to close valve before unscrewing special tool V.A.G 1318/21.
• ◆ Screw protective cap onto bleeder connection after the bleeding process is performed.