wiring diagram AUDI A4 1997 B5 / 1.G ATQ Engine Oxygen Sensor Control Checking
Page 56 of 63
24-121
Checking voltage supply for oxygen sensor
heating
Test requirement:
Fuse for oxygen sensor heating OK
Electrical Wiring Diagrams, Troubleshooting &
Component Locations binder
Fuel Pump (FP) OK, checking Page 24
-
49
.
Component location of harness connectors
Overview of component locations, page Page
24
-5
- Disconnect 4-pin harness connector leading to
respective oxygen sensor.
- Connect multimeter between terminal 1 and 2 for voltage
measurement.
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p://127.0.0.1:8080/audi/servlet/Dis
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Page 59 of 63
24-123
If there is no voltage again:
- Check wire connection from terminal 1 to Fuel
Pump (FP) relay via fuse for open circuit.
Electrical Wiring Diagrams, Troubleshooting &
Component Locations binder If voltage supply is OK:
If there is no voltage: - Connect multimeter for voltage measurement as follows:Harness connector
Terminal
Measure
to
2 (Ground -GND- activation of Engine Control Module -
ECM-) B+
- Start engine.
Specification: approx. battery voltage, possibly fluctuating
- Switch ignition off.
- Connect VAG1598/31 test box at wiring harness to ECM, do not
connect ECM Page 24
-17
.
Pa
ge 59 of 63 Ox
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11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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e=re
pair&id=AUDI.B5.FU05.24.3