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Renewing engine control unit > < Engine control unit

A3 Mk2

Wiring and component check with adapter cable, 121-pinV.A.G 1598/31 (test box)
Wiring and component check with adapter cable, 121-pin -V.A.G 1598/31- (test box)
  Note
t  The adapter cable, 121-pin -V.A.G 1598/31- 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.
   
t  Always use auxiliary measuring set -V.A.G 1527B- to connect test equipment (e.g. voltage tester -V.A.G 1526C-, hand-held multimeter -V.A.G 1594C- etc.).
  WARNING
To prevent irreparable damage to the electronic components, select appropriate measuring range before connecting the measuring cables and observe the test requirements.
–  Remove engine control unit → Chapter.
–  Connect adapter cable, 121-pin -V.A.G 1598/31- 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 event memory.
  W00-0943

Renewing engine control unit > < Engine control unit