1998 AUDI A8 ignition

28-24


If resistance values are not as specified:
If resistance values are OK: - Using multimeter and adapters from VAG1594 connector test kit,
measure resistance across both ignition wire connectors of respective
ignition coil.

Specification: 8.0-14.0 k - Replace coils.
- Check signal for power output stage page 28
-25
.
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28-25

Checking signal for power output stage

- Remove connectors from all 6 injectors (DTC
memory will have to be checked and erased
later).

- Switch ignition on.

If LED flashes: - Connect LED tester VAG1527 between engine ground and connector
terminal 3.
- Crank starter for several seconds.
LED in voltage tester must flash.
- Repeat test on 5-pin connector terminals 4 and 5.
- Replace ignition coils -N-, -N128- and -N158- with power output stage -
N122-.
Pa
ge 31 of 34 Motronic i
gnition s
ystem
11/23/2002 htt
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yp
e=re
pair&id=AUDI.B5.FU03.28.1

28-27

Checking ground for power output stage

- Disconnect 5-pin connector from ignition coils.

If LED does not light up:
Electrical Wiring Diagrams, Troubleshooting & Component Locations
binder - Connect VAG1527 LED voltage tester between B+ and terminal 2
(ground) of connector.
LED in tester must light up.
- Check wires for open circuit per wiring diagram.
Pa
ge 33 of 34 Motronic i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
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yp
e=re
pair&id=AUDI.B5.FU03.28.1

28-28

Checking voltage supply of ignition coils

Test requirement

Fuse for ignition coils OK

- Disconnect 5-pin connector from ignition coils.

- Switch ignition on.

If LED does not light up:
Electrical Wiring Diagrams, Troubleshooting & Component Locations
binder - Connect VAG1527 LED voltage tester between engine ground and
terminal 1 (B+) of connector.
LED in tester must light up.
- Check wires for open circuit per wiring diagram.
- Check fuse for ignition coils.
Pa
ge 34 of 34 Motronic i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.28.1