audi Workshop Repair Guides

Audi Workshop Service and Repair Manuals

ABOUT US
Renewing Motronic control unit J220 > < Checking initial fuel pressure up to mechanical high-pressure pump

A3 Mk2

Wiring and component check with test boxV.A.G 1598/42
Wiring and component check with test box -V.A.G 1598/42-
  Note
t  The test box has 105 contacts. The connecting cable can be disconnected from the test box. This means that only the cable (and not the test box) has to be purchased for future engine control units with different types of connectors.
   
t  The smaller of the two connectors on the engine control unit has the contacts 1 to 60. The larger of the two connectors has the contacts 1 to 94.
t  If you want to check a wiring connection to the engine control unit, first refer to the current flow diagram to find out which connector on the engine control unit the wiring connection leads to. If this is a wire which leads to the 60-pin connector (e.g. the activation wire for the intake manifold change-over valve, T60/27), then attach the smaller of the two connectors to connection “A” of the test box -V.A.G 1598/42- (using adapter cable -V.A.G 1598/39–1-) and measure to pin 27.
  A24-0622
t  If a wiring connection leads to the 94-pin connector (according to current flow diagram), then connect the larger of the two connectors using adapter cable -V.A.G 1598/39–2- as follows: The connector marked “A” must be attached to connection “A” on the test box -V.A.G 1598/42- and the connector marked “B” must be attached to connection “B” on the test box -V.A.G 1598/42-.
t  The test box -V.A.G 1598/42- is designed so it can be connected both to the wiring harness for the engine control unit and to the engine control unit itself at the same time.
t  The advantage of this is that the electronic engine control system remains fully functional when the test box is connected (for example, for measuring signals when the engine is running).
t  The relevant test procedure will state whether it is necessary to also connect the engine control unit to the test box.
  WARNING
To prevent damage to the electronic components, select appropriate measuring range before connecting the measuring cables and observe the test requirements.
–  Remove Motronic control unit -J220- → Chapter.
–  Connect test box -V.A.G 1598/42- to wiring harness connector. The earth clip on the test box must be connected to the negative battery terminal. The instructions for performing the individual tests indicate whether or not the engine control unit itself also needs to be connected to the test box.
–  Carry out test as described in appropriate repair procedures.
Installing engine control unit
Installation is performed in the reverse sequence; the engine control unit must be installed with the protective housing. New shear bolts must be used.
Perform the following after reconnecting engine control unit:
–  Interrogate and, if necessary, erase fault memory → VAS 5051 vehicle diagnostic, testing and information system.
  A24-0622

Renewing Motronic control unit J220 > < Checking initial fuel pressure up to mechanical high-pressure pump