Audi Workshop Service and Repair Manuals

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required

• ◆ V.A.G 1551 Fault reader

Note:

The vehicle system tester V.A.G 1552 can be used instead of the fault reader V.A.G 1551, however a print-out is not possible.

• ◆ V.A.G 1551/3 Cable

Test conditions

• ● → The fuses must be OK.
• ● The battery voltage must be at least 11.5 V.
• ● All electrical consumers, e.g. lights and rear window heating must be switched off.
• ● No faults must be stored in fault memory

=> Repair group 01; Fault memory; Interrogating and erasing fault memory of engine control unit

• ● Coolant temperature must be at least 80 °C, =>display group 01, display zone 2.

Checking activation

• ‒ Via final control diagnosis, first check activation of activated charcoal filter solenoid valve 1 (tank breathing valve)

=> Repair group 01; Final control diagnosis; Performing final control diagnosis

If activation is OK:

• ‒ Carry out functional check
  .

Functional check

• ‒ Connect fault reader V.A.G 1551 (V.A.G 1552). Start engine and select the engine control unit with the "Address word" 01. Connecting fault reader and selecting engine control unit:

=> Repair group 01; General to self-diagnosis; Connecting fault reader V.A.G 1551 and selecting engine control unit

• ‒ Press keys 0 and 4 for the function "Introduction of basic setting" and confirm entry with Q key.

• ‒ Press keys 0, 0 and 1 for "Display group number 1" and confirm entry with Q key.

Only continue with the test when

• ● The coolant temperature is above 80°C
  in -display zone 2-

• ‒ Change to display group 70 as follows:
• ‒ Press C key.

• ‒ Press keys 0, 7 and 0 for "Display group number 70" and confirm entry with Q key.

Note:

The engine must not be loaded during this diagnosis because the diagnosis will be interrupted and will not be started again until the engine is revved-up.

When the diagnosis is initiated by the engine control unit, the display in display zone 4 jumps from "Test OFF" to "Test ON".

• ‒ Run engine at idling speed until the specification "TBV OK" is displayed in display zone 4.

Note:

TBV stands for tank breather valve (activated charcoal filter solenoid valve 1).

• ‒ Press ⇒key.
• ‒ Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
• ‒ Switch off ignition.

If "TBV n.OK is indicated in display zone 4:

• ‒ Check breather lines to activated charcoal filter for possible kinks.
• ‒ Start final control diagnosis and activate tank venting valve (N80):

=> Repair group 01; Final control diagnosis; Performing final control diagnosis

• ‒ Interrogate fault memory:

=> Repair group 01; Fault memory; Interrogating and erasing fault memory of engine control unit