2000 AUDI A8 catalytic converter

24-78


Oxygen sensors and oxygen sensor
control before catalytic converter,
checking

Special Tools and Equipment

VAG1526A
VAG1594A
VAG1598/31
VAS5051 with VAG5051/1
- or
VAG1551 with VAG1551/3B
Pa
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11/23/2002 htt
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24-82
Significance of 3 digit indication of display group 030 X
X
X
Display fields 1 to 4
X Oxygen sensor control
0= not active
1 = active
X Operational readiness of oxygen sensor
0= not active
1 = active
X Condition of oxygen sensor heating
0= not active
1 = active
Notes:

The oxygen sensor control of the oxygen sensors behind catalytic converter (B1-S2 and B2-S2) are not active at certain
operation points without engine load, that means that the third position of the oxygen sensor controls behind catalytic
converter can fluctuate between 0 and 1.
The first position of the 3 digit indication (heating) fluctuates between 0 and 1 at certain operation points.
Pa
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11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
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24-84

1 2 3 4
Display group 033: Oxygen sensor control before catalytic converter
Display
xx.x % x.xxx volts
xx.x % x.xxx V
Indicated
Oxygen sensor control
Bank1 Oxygen sensor voltage
bank 1 Oxygen sensor control
Bank2 Oxygen sensor voltage
bank 2
Functional
range -25.0 to 25.0 % 0.100 to 1.000 V
-25.0 to 25.0 % 0.100 to 1.000 V

Specified
value Value must fluctuate by
at least 2 % in the range
10.0 to 10.0 % Value must fluctuate
approx. 0.3 V in the
range 0.100 to 1.000
volts Value must fluctuate by
at least 2 % in the range
10.0 to 10.0 % Value must fluctuate
approx. 0.3 V in the
range 0.100 to 1.000
volts
Notes
If specified value is not
obtained Page 24
-85


If specified value is not
obtained Page 24
-85


Pa
ge 10 of 63 Ox
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11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
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24-86

- Press -C- button.

- Press buttons -0-, -3- and -2- to select "display
group number 032" and press -Q- button to
confirm input. System in Basic Setting 32
1
2
3
4

When indicated on display:
- Check oxygen sensor control in display fields 1 to 4:

Display fields

1 2 3 4
Display group 032: Oxygen sensor adaptation values before catalytic converter
Display
xx.x %
xx.x %
xx.x %
xx.x %
Indicated
Oxygen sensor
adaptation value
Bank 1 at idle
(additive) Oxygen sensor adaptation
value bank 1 at partial
throttle
(multiple) Oxygen sensor
adaptation value
Bank 2 at idle
(additive) Oxygen sensor adaptation
value bank 2 at partial
throttle
(multiple)
Functional
range -25.0 to 25.0 %
-25.0 to 25.0 %
-25.0 to 25.0 %
-25.0 to 25.0 %

Specified
value -10.0 to 10.0 %
can fluctuate
slightly -10.0 to 10.0 %
can fluctuate slightly -10.0 to 10.0 %
can fluctuate
slightly -10.0 to 10.0 %
can fluctuate slightly
Notes
If specified value is not obtained Page 24
-87

Pa
ge 12 of 63 Ox
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en sensor control, checkin
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11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.24.3

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
Pa
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11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
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pair&id=AUDI.B5.FU05.24.3

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.
Pa
ge 22 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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pair&id=AUDI.B5.FU05.24.3

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
Pa
ge 24 of 63 Ox
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en sensor control, checkin
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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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pair&id=AUDI.B5.FU05.24.3

before catalytic converter (bank 1)
Pa
ge 25 of 63 Ox
yg
en sensor control, checkin
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11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.24.3