Audi A8 1994 Service Manual page 70

Audi A8 1994 ➤
Motronic injection and ignition system (6-cylinder) - Edition 02.1999
Testing voltage supply to intake manifold change-over valve
-N156
- -> Connect diode test lamp V.A.G 1527 between engine earth and socket 1 on connector using test leads
from auxiliary test set V.A.G 1594.
- Operate the starter briefly.
The diode test lamp should light up.
- If the diode test lamp does not light up:
- Test fuse for intake manifold change-over valve.
=> Current flow diagrams, Electrical fault finding and Fitting locations binder
If the fuse is OK:
- Test for open circuit and short circuit in wiring between fuel pump relay and socket 1 on connector via fuse
for intake manifold change-over valve.
=> Current flow diagrams, Electrical fault finding and Fitting locations binder
If the voltage supply is OK, test activation. => Page
Testing activation of intake manifold change-over valve
- Connect diode test lamp V.A.G 1527 between sockets 1 (positive) and 2 on connector for intake manifold
change-over valve using test leads from auxiliary test set V.A.G 1594.
-> Perform final control diagnosis and activate intake manifold change-over valve
=>Page 15 .
Final control diagnosis
Intake manifold press. change valve -
N156
If the diode test lamp does not flash or lights up continuously, test the wiring.
Testing wiring
- Connect test box V.A.G 1598/31 to wiring harness for engine control unit. Do not connect to the engine
control unit itself.
=> Page 30 .
66
24 - Mixture preparation, Injection
66
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