buttons AUDI A6 1995 C5 / 2.G ATQ Engine Oxygen Sensor Control Checking

24-79

Notes:

For the defined troubleshooting procedure, it is
possible, to switch oxygen sensor control off by
selecting display group 099 under "basic
setting" and switch it on again under "read
measuring value block".
After selecting display group 099 (either in
"basic setting" or "read measuring value
block"), it is possible to switch back and forth
between "basic setting" (function 04) and "read
measuring value block" (function 08) by
pressing buttons 4 or 8 on the VAG1551.
Once function 04 "basic setting" is exited,
oxygen sensor control is automatically switched
on again.

Test requirements:
Road test performed and DTC memory
erased.
Coolant temperature at least 80 C
Display group 4, display field 3
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Function test

- 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:
Note:
During basic setting, the Evaporative Emission (EVAP) canister purge
regulator valve (EVAP valve -N80-) is closed and the A/C compressor is
switched off - Press buttons -0- and -4- to select "Initiate basic setting" and press -Q-
button to confirm input.
Basic Settin
g
Q
Input displa
y group number XXX

When indicated on display:
- Press buttons -0-, -3- and -0- to select "display group number 030" and
press -Q- button to confirm input.
System in Basic Setting 30
1
2
3
4

When indicated on display:
Note: - Check oxygen sensor status in display fields 1 and 3.
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Checking oxygen sensor adaptation values
and control

- Press -C- button.Basic Setting
Q
Input displa
y group number XXX

When indicated on display:
- Press buttons -0-, -3- and -3- to select "display group number 033" and
press -Q- button to confirm input.
System in Basic Setting 33
1
2
3
4

When indicated on display:
- Check oxygen sensor control in display fields 1 and 3.
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- 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

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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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- 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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24-99

Rapid data transfer
HELP
Select function XX

When indicated on display:
Note:
During basic setting, the Evaporative Emission (EVAP) canister purge
regulator valve (EVAP valve -N80-) is closed and the A/C compressor is
switched off - Press buttons -0- and -4- to select "Initiate basic setting" and press -Q-
button to confirm input.
Basic Settin
g
Q
Input displa
y 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
2800 and 3200 RPM.
- Continue test as soon as display field 2 indicates an exhaust
temperature of more than 380 C
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- Press -C- button.

- Let engine continue to idle Basic Setting
Q
Input displa
y group number XXX

When indicated on display:
- Press buttons -0-, -3- and -0- to select "display group number 030" and
press -Q- button to confirm input.
System in Basic Setting 30
1
2
3
4

When indicated on display:
Note:
"Oxygen sensor status" indicates status of oxygen sensor control and
oxygen sensors. - Check oxygen sensor status for oxygen sensor behind catalytic
converter in display fields 2 and 4.
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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

- Press -C- button.Basic Setting
Q
Input displa
y group number XXX

When indicated on display:
- Press buttons -0-, -4- and -3- to select "display group number 043" and press -Q-
button to confirm input.
System in Basic Setting 43
1
2
3
4

When indicated on display:
- Check specified value in display field 4 after indication "Test ON" appears:
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Display fields

1 2 3 4
Display group 043: Oxygen sensor aging, oxygen sensor behind catalytic converter (bank 1)
Display xxxx/min
xxx C
x.xxx V
---
Indicated Engine speed
(RPM) Exhaust
temperature Voltage of oxygen sensor
behind catalytic converter,
bank 1 Diagnostic condition
Functional
range 630 to 6800
RPM 70 to 850 C
0.100 to 1.000 volts Test OFF
Test ON
B1-S2 OK
B1-S2 not OK
Specified
value 1800 to 2400
RPM above 380 C 0.100 to 1.000 volts B1-S2 OK
Notes



If specified value is not obtained
Check oxygen sensor heater Page
24
-116

If specified value B1-S2 OK" is obtained:

- Press -C- button.

- Press buttons -0-, -4- and -4- to select "display
group number 044" and press -Q- button to
confirm input.
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