fuse diagram AUDI A4 1997 B5 / 1.G APB Engine Oxygen Sensor Control Checking Workshop Manual

24-117

Checking voltage supply for oxygen sensor
heater
Component location of 4-pin harness connector
of oxygen sensors Page 24
-5 .

- Check fuse for oxygen sensor heater

Electrical Wiring Diagrams, Troubleshooting &
Component Locations
- Disconnect 4-pin harness connector of particular
oxygen sensor.

If there is no voltage reading: - Connect hand-held multimeter (voltage measurement range) between
sockets 1 (B+) and 2 (Ground (GND)) using test leads from VAG1594
connector test kit.
- Operate starter briefly.
Specified value: approx. battery voltage
- Connect hand-held multimeter (voltage measurement range) between
socket 1 (B+) and vehicle Ground (GND) using test leads from
VAG1594 connector test kit.
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24-118

- Operate starter briefly.

Specified value: approx. battery voltage
If there is still no voltage reading:

- Check for open circuit and/or short circuit in
wiring between fuel pump relay and socket 1 on
the relevant oxygen sensor connector (on wiring
harness) via fuse.

Electrical Wiring Diagrams, Troubleshooting &
Component Locations If the voltage supply is OK:

- Connect hand-held multimeter (voltage measurement range) between
socket 2 (switched Ground (GND) connection from engine control
module) and B+ terminal using test leads from VAG1594 connector test
kit.
Pa
ge 46 of 61 Ox
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en sensor control, checkin
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11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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e=re
pair&id=AUDI.B5.FU04.24.2