Audi Workshop Service and Repair Manuals

Notes:

• ◆ The test box V.A.G 1598/31 is designed in such a way that it can be connected simultaneously to the engine control unit wiring harness and to the engine control unit itself.
• ◆ This has the advantage that the electronic motor control system remains fully functional when the test box is connected (for example, for measuring signals when the engine is running).
• ◆ Whether the engine control unit has to be additionally connected to the test box or not is described in the respective test procedures.
• ◆ Always use adapter set V.A.G 1594 A for connecting up measuring instruments (e.g. voltage tester V.A.G 1527 B, hand-held multimeter V.A.G 1526 A etc.)

Special tools and workshop equipment required

• ◆ V.A.G 1598/31

Procedure

• ‒ Switch ignition off.

• ‒ Remove engine control unit .
• ‒ → Connect V.A.G 1598/31 test box to connector on wiring harness. The earth clip on the test box (not visible in the illustration) has to be connected to earth. Whether or not the engine control unit has to be additionally connected to the test box is described in the respective test procedures.
• ‒ Carry out test as described in the appropriate repair procedures.

Important note:

After reinstalling the engine control unit the following operations must be performed:

• ‒ Perform adaption of throttle valve control unit -J338 => Page 24-125.
• ‒ Adaption of kickdown function on vehicles with automatic gearbox .
• ‒ Interrogate fault memory and erase, if necessary => Page 01-9.
• ‒ If fault memory is erased the readiness code must be produced again => Page 01-69.

Note:

In the first adaption phase irregular idling and slight jolting when driving are possible.