1995 AUDI A6 sensor

24-90

Check oxygen sensor wires bank 1 for Heated
Oxygen Sensor (HO2S) 2 -G39-.
Component location of harness connectors
Overview of component locations, page Page
24
-5

- Disconnect black 4-pin harness connector to
bank 1 Heated Oxygen Sensor (HO2S) -G39-.

- Connect VAG1598/31 test box at wiring harness
to ECM, do not connect ECM Page 24
-17
.

- Check the following wire connections for open circuit.Harness connector
Terminal
VAG1598/31 test box
Socket
3 51
4 70
- Repair open circuit if necessary.
- Check wires to each other for short circuit.Harness connector
Terminal
VAG1598/31 test box
Socket
4 51
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24-91


If no malfunctions are found in wires:
Check oxygen sensor wires bank 2 for Heated Oxygen Sensor
(HO2S) 2 -G108-.
Component location of harness connectors Overview of component
locations, page Page 24
-5 - Check shielded wire for short circuit to sensor wires.
Harness connector
Terminal
VAG1598/31 test box
Socket
3 32
4 32
- Replace Engine Control Module (ECM) Page 24
-21
.
- Disconnect black 4-pin harness connector to bank 2 Heated Oxygen
Sensor (HO2S) 2 -G108-.
- Connect VAG1598/31 test box at wiring harness to ECM, do not
connect ECM Page 24
-17
.
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24-92


If no malfunctions are found in wires: - Check the following wire connections for open circuit.Harness connector
Terminal
VAG1598/31 test box
Socket
3 12
4 13
- Repair open circuit if necessary.
- Check wires to each other for short circuit.Harness connector
Terminal
VAG1598/31 test box
Socket
4 12
- Check shielded wire for short circuit to sensor wires.Harness connector
Terminal
VAG1598/31 test box
Socket
3 32
4 32
- Replace Engine Control Module (ECM) Page 24
-21
.
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24-93

Oxygen sensor aging (oxygen sensor
before catalytic converter), checking


Special Tools and Equipment

VAG1788/10 RPM adjuster

Test requirement:
VAS5051 with VAG5051/1
orVAG1551 with VAG1551/3BCoolant temperature at least 80 C Display group 4, display field 3
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24-94

Test sequence

- Connect VAS5051 tester or VAG1551 scan tool
and select the control module for engine
electronics using "address word" 01 Page 01
-
9 .

Engine must run at idle for this.Rapid data transfer
HELP
Select function XX

When indicated on display:
- Press buttons -0- and -4- to select "Initiate basic setting" and press -Q-
button to confirm input.
Basic Settin
g
Q
Input display group number XXX

When indicated on display:
- Press buttons -0-, -3- and -4- to select "display group number 034" and
press -Q- button to confirm input.
System in Basic Setting 34
1
2
3
4

When indicated on display:
Note:
This process can take a few minutes. - Use VAG1788/10 RPM adjuster to adjust engine speed to between
1000 and 2400 RPM.
- Check specified value in display field 4 after indication "Test ON"
appears:
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24-95


Display fields

1 2 3 4
Display group 034: Oxygen sensor aging diagnostic, oxygen sensor before catalytic converter (bank 1)
Display xxxx/min
xxx C
x.x s
---
Indicated Engine speed
(RPM) Exhaust
temperature Period duration
Oxygen sensor before
Catalytic converter Diagnostic condition
Functional
range 630 to 6800
70 to 850 C
0 to 3.0 s
Test OFF
Test ON
B1-S2 OK
B1-S2 not OK
Specified
value 1000 to 2400
RPM above 380 C 0.1 to 1.8 s B1-S2 OK
Notes


If the specified value is not reached, replace oxygen sensor 1
before catalytic converter (bank 1)
Note for display field 2:
Calculated value from engine speed and engine load.
Note for display fields 3 and 4:
Period duration is the time between two oxygen sensor voltage jumps (e.g. rich - lean - rich) and is therefore a measurement
of the aging condition of the oxygen sensor. If the specified time is exceeded, display field 4 will indicate = B1-S1 not OK.
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- Press -C- button.Basic Settin
g
Q
Input display group number XXX

When indicated on display:
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24-96

- Press buttons -0-, -3- and -5- to select "display
group number 035" and press -Q- button to
confirm input. System in Basic Setting 35
1
2
3
4

When indicated on display:
Note:
The test in display group 035 is activated simultaneously with the test in
display group 034 Therefore the test result is indicated immediately after
display group 035 is selected. - Check specified value in display field 4.

Display fields

1 2 3 4
Display group 035: Oxygen sensor aging diagnostic, oxygen sensor before catalytic converter (bank 2)
Display xxxx/min
xxx C
x.x s
---
Indicated Engine speed
(RPM) Exhaust
temperature Period duration
Oxygen sensor before
Catalytic converter Diagnostic condition
Functional
range 630 to 6800
70 to 850 C
0 to 3.0 s
B1-S2 OK
B1-S2 not OK
Specified
value 1000 to 2400
RPM above 380 C 0.1 to 1.8 s B1-S2 OK
Notes


If the specified value is not reached, replace oxygen sensor 2
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