engine AUDI A4 1995 B5 / 1.G APB Engine Oxygen Sensor Control Checking Owner's Manual
[x] Cancel search | Manufacturer: AUDI, Model Year: 1995, Model line: A4, Model: AUDI A4 1995 B5 / 1.GPages: 61, PDF Size: 0.27 MB
Page 46 of 61

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.
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Page 47 of 61

24-119
- Start engine.
Specified value: approx. battery voltage
(fluctuating)
Note:
At certain points in the operating range the
engine control module continuously "switches"
the Ground (GND) connection to the oxygen
sensor heater. That means, it repeatedly
connects and disconnects the Ground (GND)
connection at these points. For this reason the
voltage reading on the tester may fluctuate.
- Switch ignition off.
If there is no voltage reading:
- Connect VAG1598/31 test box to wiring harness
for engine control module. Do not connect to the
engine control module itself Page 24
-20
.
- Check for open circuits in the following wiring connection:
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Page 51 of 61

24-123
If Specified value is obtained:
- Replace relevant oxygen sensor.
Checking oxygen sensor wiring for Heated
Oxygen Sensor (HO2S) -G39
Component location of 4-pin harness connector
of oxygen sensor Page 24
-5 .
- Disconnect 4-pin connector (black) for Heated
Oxygen Sensor (HO2S) -G39.
- Connect VAG1598/31 test box to wiring harness
for engine control module. Do not connect to
engine control module itself Page 24
-20
.
Electrical Wiring Diagrams, Troubleshooting & Component Locations - Check following wiring connections for open circuits:
Connector on wiring harness,
socket
VAG1598/31 test box socket
3 51
4 70
Resistance in wiring: max. 1.5 Ohm
Pa
ge 51 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
Page 52 of 61

24-124
Electrical Wiring Diagrams, Troubleshooting & Component Locations
Electrical Wiring Diagrams, Troubleshooting & Component Locations
If no malfunction is identified in the wiring: - Check wiring also on 4-pin harness connector for short circuits to each
other.
Connector on wiring harness,
socket
VAG1598/31 test box socket
4 51
Specified value: infinite ohms (open circuit)- Check shielded wire for short circuit to sensor wiring.
Connector on wiring harness,
socket
VAG1598/31 test box socket
4 32
3 32
Specified value: infinite ohms(open circuit)- Replace Motronic Engine Control Module (ECM) -J220 Page 24
-24
.
Pa
ge 52 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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pair&id=AUDI.B5.FU04.24.2
Page 53 of 61

24-125
Checking wiring for Oxygen Sensor (O2S)
Behind Three Way Catalytic Converter (TWC)
-G130
Component location of 4-pin harness connector
of oxygen sensor Page 24
-5 .
- Disconnect 4-pin connector (black) for Oxygen
Sensor (O2S) Behind Three Way Catalytic
Converter (TWC) -G130.
- Connect VAG1598/31 test box to wiring harness
for engine control module. Do not connect to the
engine control module itself Page 24
-20
.
Electrical Wiring Diagrams, Troubleshooting & Component Locations - Check following wiring connections for open circuits:
Connector on wiring harness,
socket
VAG1598/31 test box socket
3 68
4 69
Resistance in wiring: max. 1.5 ohm
Pa
ge 53 of 61 Ox
yg
en sensor control, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.2
Page 54 of 61

24-126
Electrical Wiring Diagrams, Troubleshooting & Component Locations
Electrical Wiring Diagrams, Troubleshooting & Component Locations
If no malfunction is identified in the wiring: - Check wiring also on 4-pin harness connector for short circuits to each
other.
Connector on wiring harness,
socket
VAG1598/31 test box socket
4 68
Specified value: infinite ohms (open circuit)- Check shielded wire for short circuit to sensor wiring.
Connector on wiring harness,
socket
VAG1598/31 test box socket
4 32
3 32
Specified value: infinite ohms (open circuit)- Replace Motronic Engine Control Module (ECM) -J220 Page 24
-24
.
Pa
ge 54 of 61 Ox
yg
en sensor control, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.2
Page 55 of 61

24-127
Checking wiring for Heated Oxygen Sensor
(HO2S) 2 -G108
Component location of 4-pin harness connector
of oxygen sensor Page 24
-5 .
- Disconnect 4-pin connector (black) for Heated
Oxygen Sensor (HO2S) 2 -G108.
- Connect VAG1598/31 test box to wiring harness
for engine control module. Do not connect to the
engine control module itself Page 24
-20
.
Electrical Wiring Diagrams, Troubleshooting & Component Locations - Check following wiring connections for open circuits:
Connector on wiring harness,
socket
VAG1598/31 test box socket
3 12
4 13
Resistance in wiring: max. 1.5 ohm
Pa
ge 55 of 61 Ox
yg
en sensor control, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.2
Page 56 of 61

24-128
Electrical Wiring Diagrams, Troubleshooting & Component Locations
Electrical Wiring Diagrams, Troubleshooting & Component Locations
If no malfunction is identified in the wiring: - Check wiring also on 4-pin harness connector for short circuits to each
other.
Connector on wiring harness,
socket
VAG1598/31 test box socket
4 12
Specified value: infinite ohms (open circuit)- Check shielded wire for short circuit to sensor wiring.
Connector on wiring harness,
socket
VAG1598/31 test box socket
4 32
3 32
Specified value: infinite ohms (open circuit)- Replace Motronic Engine Control Module (ECM) -J220 Page 24
-24
.
Pa
ge 56 of 61 Ox
yg
en sensor control, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.2
Page 57 of 61

24-129
Checking wiring for Oxygen Sensor (O2S) 2
Behind Three Way Catalytic Converter (TWC)
-G131
Component location of 4-pin harness connector
of oxygen sensor Page 24
-5 .
- Disconnect 4-pin connector for Oxygen Sensor
(O2S) 2 Behind Three Way Catalytic Converter
(TWC) -G131
- Connect VAG1598/31 test box to wiring harness
for engine control module. Do not connect to the
engine control module itself Page 24
-20
.
Electrical Wiring Diagrams, Troubleshooting & Component Locations - Check following wiring connections for open circuits:
Connector on wiring harness,
socket
VAG1598/31 test box socket
3 10
4 11
Resistance in wiring: max. 1.5 ohm
Pa
ge 57 of 61 Ox
yg
en sensor control, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.2
Page 58 of 61

24-130
Electrical Wiring Diagrams, Troubleshooting & Component Locations
Electrical Wiring Diagrams, Troubleshooting & Component Locations
If no malfunctions are identified in the wiring: - Check wiring also on 4-pin harness connector for short circuits to each
other.
Connector on wiring harness,
socket
VAG1598/31 test box socket
4 10
Specified value: infinite ohms (open circuit)- Check shielded wire for short circuit to sensor wiring.
Connector on wiring harness,
socket
VAG1598/31 test box socket
4 32
3 32
Specified value: infinite ohms (open circuit)- Replace Motronic Engine Control Module (ECM) -J220 Page 24
-24
.
Pa
ge 58 of 61 Ox
yg
en sensor control, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.2