battery location AUDI A4 1998 B5 / 1.G APB Engine Ignition System Checking

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If malfunction remains at the same cylinder.

- Disconnect harness connector from ignition
coil.

Electrical Wiring Diagrams, Troubleshooting & Component Locations
If the Ground (GND) connection is OK. - Check Ground (GND) connection between socket 4a and engine
Ground (GND) for open circuit and short circuit to B+. - Repair any open/short circuit as necessary.
- Connect hand-held multimeter (voltage range) to terminal 15 of
harness connector and Ground (GND).
- Disconnect harness connector from fuel injector of cylinder to be
tested.
- Operate starter.
Specified value: approx. battery voltage
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Control module voltage supply,
checking


Test requirements:

Fuse for Engine Control Module (ECM) OK

Electrical Wiring Diagrams, Troubleshooting &
Component Locations

Battery voltage at least 11 V
Generator OK

- Connect test box VAG1598/31 to wiring harness
for engine control module. Do not connect to the
engine control module itself. Page 24
-20
.

- Switch ignition on.

Note:

The B+ voltage supply for the engine control
module comes via terminal 3 (terminal 15) and
terminal 62 (terminal 30).

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Page 37 of 64

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- Connect hand-held multimeter VAG1526
(voltage measurement range) to the following
contacts on the test box:

Contact
Specification
3 + 2 approx.
battery voltage
3 + 1 approx.
battery voltage
62 + 2 approx.
battery voltage
If the specifications are not obtained:

- Check wiring.

Electrical Wiring Diagrams, Troubleshooting &
Component Locations
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11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.28.1