Volkswagen Workshop Service and Repair Manuals

Engine codes: APE, AUA, AUB, AQQ

In a no-current situation the solenoid valve is closed.

Checking activation:

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

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

• ● Coolant temperature must be at least 80 °C, =>display group 04, display zone 3.

• ● → Fuse No. SB30 must be OK.

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 "Introduce basic setting" function and confirm entry with Q 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"

• ‒ Leave the engine running at idle until the result of short diagnosis is displayed
       Specification: "TVV OK"

Note:

TVV stands for tank vent valve (activated charcoal filter system solenoid valve 1).

If the display jumps from "Test ON" to "Test OFF" during the test, rev up briefly and the test will be repeated.

If "TVV not OK" appears in display zone 4:

• ‒ Initiate the final control diagnosis and activate the activated charcoal filter solenoid valve -N80:

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

If the specification "TVV OK" is obtained:

• ‒ Press ⇒key.

• ‒ Press keys 0 and 6 for the "End data transfer" function and confirm input with the Q key.
• ‒ Switch off ignition.