wiring AUDI A4 1997 B5 / 1.G AWM Engine Oxygen Sensor Control Checking Workshop Manual
[x] Cancel search | Manufacturer: AUDI, Model Year: 1997, Model line: A4, Model: AUDI A4 1997 B5 / 1.GPages: 46, PDF Size: 0.3 MB
Page 12 of 46

24-82
If specified value is not obtained:
- Check oxygen sensor wiring.
If specified value is obtained:
- Replace Heated Oxygen Sensor (HO2S)-G39-
.
Checking oxygen sensor wires
Note:
Coolant reservoir screws must be removed and coolant reservoir must be
placed to side in order to access the harness connector. The coolant
hoses can remain connected. - Disconnect 6-pin harness connector (black) -2- to Heated Oxygen
Sensor (HO2S) -G39- before catalytic converter.
- Connect VAG1598/31 test box at wiring harness to Engine Control
Module (ECM), do not connect ECM Page 24
-19
.
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Page 13 of 46

24-83
Electrical Wiring Diagrams, Troubleshooting & Component Locations
If wire connection is OK: - Check the following wire connections for open circuit.Harness connector
Terminal
VAG1598/31 test box
Socket
1 70
2 71
5 51
6 52
- Repair open circuit if necessary.- Check wires to each other for short circuit.
- Replace Engine Control Module (ECM) Page 24
-22
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Page 20 of 46

24-90
Test requirements:
Coolant Temperature at least 80 C.
Fuse for oxygen sensor heating OK
Electrical Wiring Diagrams, Troubleshooting &
Component Locations
Test sequence
Note:
Coolant reservoir screws must be removed and coolant reservoir must be
placed to side in order to access the harness connector. The coolant
hoses can remain connected. - Disconnect 6-pin harness connector (black) -2- to Heated Oxygen
Sensor (HO2S) -G39- before catalytic converter.
If specified value is not obtained: - Connect multimeter between terminal 3 and 4 for resistance
measurement.
Specified value at room temperature: 2.5 to 10
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Page 23 of 46

24-92
- Operate starter briefly.
Specification: approx. battery voltage
If there is no voltage again:
- Check wire connection from terminal 3 of
connector to Fuel Pump (FP) relay via fuse for
open circuit:
Electrical Wiring Diagrams, Troubleshooting &
Component Locations
If voltage supply is OK:
Note: - Connect multimeter for voltage measurement as follows:Harness connector
Terminal
Measure
to
4 (Ground -GND- activation of Engine Control Module -
ECM-) B+
- Start engine.
Specification: approx. battery voltage
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Page 25 of 46

24-93
- Switch ignition off.
If there is no voltage:
- Connect VAG1598/31 test box at wiring harness
to Engine Control Module (ECM), do not connect
ECM Page 24
-19
.
Electrical Wiring Diagrams, Troubleshooting & Component Locations
If wire connection is OK, but there is no Ground (GND) supply for oxygen
sensor heating: - Check the following wire connection for open circuit:Harness connector
Terminal
VAG1598/31 test box
Socket
4 5
- Repair open circuit if necessary.- Replace Engine Control Module (ECM) Page 24
-22
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Page 34 of 46

24-102
Evaluation display group 037 Display field: 2
Possible cause
Corrective action
constant about
0.450 V
Open circuit in wire 4 between oxygen sensor
and control module - Check primary voltage Page 24
-104
Open circuit in wire 3 between oxygen sensor
and control module
larger than
0.950 V Short circuit to B+ in wire 4 between oxygen
sensor and control module - Check oxygen sensor wiring, oxygen sensor after
catalytic converter Page 24
-105
smaller than
0.100 V
Short circuit to Ground (GND) in wire 4 between
oxygen sensor and control module
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Page 37 of 46

24-105
If specified value is not obtained:
- Check oxygen sensor wiring.
If specified value is obtained:
- Replace Oxygen Sensor (O2S) behind Three
Way Catalytic Converter (TWC) -G130-.
Checking oxygen sensor wires
Note:
Coolant reservoir screws must be removed and coolant reservoir must be
placed to side in order to access the harness connector. The coolant
hoses can remain connected. - Disconnect 4-pin harness connector -1- (brown) to Oxygen Sensor
(O2S) behind Three Way Catalytic Converter (TWC) -G130-.
- Connect VAG1598/31 test box at wiring harness to Engine Control
Module (ECM), do not connect ECM Page 24
-19
.
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Page 38 of 46

24-106
Electrical Wiring Diagrams, Troubleshooting & Component Locations
If wire connection is OK: - Check the following wire connections for open circuit.Harness connector
Terminal
VAG1598/31 test box
Socket
3 68
4 69
- Repair open circuit if necessary.- Check wires to each other for short circuit.
- Replace Engine Control Module (ECM) Page 24
-22
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Page 40 of 46

24-108
Test requirements:
Coolant Temperature at least 80 C.
Fuse for oxygen sensor heating OK
Electrical Wiring Diagrams, Troubleshooting &
Component Locations
Test sequence
Note:
Coolant reservoir screws must be removed and coolant reservoir must be
placed to side in order to access the harness connector. The coolant
hoses can remain connected. - Disconnect 4-pin harness connector -1- (brown) to Oxygen Sensor
(O2S) behind Three Way Catalytic Converter (TWC) -G130-.
If specified value is not obtained: - Connect multimeter between terminal 1 and 2 for resistance
measurement.
Specified value at room temperature: 6.4 to 47.5
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Page 43 of 46

24-110
- Operate starter briefly.
Specification: approx. battery voltage
If there is no voltage again:
- Check wire connection from terminal 1 of
connector to Fuel Pump (FP) relay via fuse for
open circuit:
Electrical Wiring Diagrams, Troubleshooting &
Component Locations
If voltage supply is OK:
- 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.
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pair&id=AUDI.B5.FU07.24.2