buttons AUDI A4 1995 B5 / 1.G APB Engine Oxygen Sensor Control Checking Workshop Manual

24-82

Notes:

For the defined troubleshooting procedure, it is
possible to switch off the oxygen sensor control
by selecting Display Group 99 in "Basic Setting"
mode and to switch it on again by selecting
Display Group 99 in "Read Measuring Value
Block" mode.
After selecting Display Group 99 (either in
"Basic Setting" mode or in "Read Measuring
Value Block" mode) it is possible to switch back
and forth between function 04 ("Basic Setting")
and function 08 "Read Measuring Value Block")
by pressing buttons 4 and 8 on VAG1551 scan
tool.
When exiting the "Basic Setting" mode (function
04) the oxygen sensor control is automatically
switched on again.

Test conditions
Perform road test and do not erase DTC
memory.
Coolant temperature at least 85 C (Display
group 004, display field 3)
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24-83

Checking function

- Connect vehicle diagnostic, testing and
information system VAS5051 or VAG1551 scan
tool and select engine electronics control
module by entering address word "01" Page
01
-9 . When doing this the engine must be at
idle.
Rapid data transfer
HELP
Select function XX

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

Indicated on display
- Press buttons -0-, -3- and -0- to select "display group number 030" and
confirm entry with -Q- button.
System in Basic Setting 30
1
2
3
4

Indicated on display: (1 - 4 display fields) - Check oxygen sensor status in display fields 1 to 4.
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24-86

Checking oxygen sensor adaptation and
oxygen sensor control

- Connect vehicle diagnostic, testing and
information system VAS5051 or VAG1551 and
select engine electronics control module by
entering address word "01" Page 01
-9. When
doing this the engine must be idling.
Rapid data transfer
HELP
Select function XX

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

Indicated on display
- Press buttons -0-, -3- and -3- to select Display Group 33 and confirm
entry with -Q- button.
System in Basic Setting 33
1
2
3
4

Indicated on display: (1 - 4 display fields)
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24-87

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

Display fields

1 2 3 4
Display Group 33: Oxygen sensor control at idle speed
Display
xx.x %
xx.x V
xx.x %
xx.x V
Indicates
Oxygen sensor control,
bank 1 Oxygen sensor voltage,
bank 1 Oxygen sensor control,
bank 2 Oxygen sensor voltage,
bank 2
Work range
min.: -25.0 %
max.: 25.0 % min.: 0.000 Volt
max.: 1.000 Volt min.: -25.0 %
max.: 25.0 % min.: 0.000 Volt
max.: 1.000 Volt
Specification
-4.0 to 4.0 %
(The value must
fluctuate by 2 %) Between 0.000 and
1.000 V the voltage
should fluctuate -4.0 to 4.0 %
(The value must
fluctuate by 2 %) Between 0.000 and
1.000 V the voltage
should fluctuate
Note
If readout does not
match specification
Page 24
-89

If readout does not
match specification
Page 24
-92

If readout does not
match specification
Page 24
-89

If readout does not
match specification
Page 24
-92


- Press button -C-.

- Press buttons -0-, -3- and -3- to select "display
group number 033" and confirm entry with -Q-
button.
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24-94

Rapid data transfer
HELP
Select function XX

Indicated on display
- Press buttons -0- and -4- to select "Basic Setting" and confirm with -Q-
button.
Basic Setting
Q
Input displa
y group number XXX

Indicated on display
Test requirements - Press -0-, -3- and -4- to select "display group number 034" and confirm
with -Q- button.
Engine runs at 1900 - 2200 RPM
System in Basic Setting 34
1
2
3
4

Indicated on display
- Continue test as soon as display field 4 indicates "Test ON".
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24-96

Continuation
If specified value in display field 3 or 4 is not
obtained:

- Replace Heated Oxygen Sensor (HO2S) before
Three Way Catalytic Converter Bank 1 -G39.

Test sequence for oxygen sensor 1 before
catalytic converter bank 2

- Connect vehicle diagnostic, testing and
information system VAS5051 or VAG1551 and
select engine electronics control module by
entering address word "01" Page 01
-9. When
doing this the engine must be at idle.
Rapid data transfer
HELP
Select function XX

Indicated on display
- Press buttons -0- and -4- to select "Basic Setting" and confirm with -Q-
button.
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24-102

Test conditions

Perform road test and do not erase DTC
memory.
Coolant temperature at least 85 C (185 F)
(Display group 004, display field 3)

- Connect vehicle diagnostic, testing and
information system VAS5051 or VAG1551 scan
tool and select engine electronics control
module by entering address word "01" Page
01
-9 . When doing this the engine must be at
idle.
Rapid data transfer
HELP
Select function XX

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

Indicated on display
- Press buttons -0-, -3- and -4- to select "display group number 034" and
confirm entry with -Q- button.
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24-103

System in Basic Setting 34
1
2
3
4

When indicated on display:
Note:
This process can take a few minutes. - Adjust engine speed using VAG1788/10 to 2800 - 3200 RPM.
- Continue test as soon as display field 2 indicates an exhaust
temperature of more than 320 C. - Press -C- button.
- Adjust engine speed using VAG1788/10 to 1900 - 2200 RPM.
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:
"Oxygen sensor status" indicates status of oxygen sensor control and
oxygen sensor. - Check oxygen sensor status for oxygen sensor behind catalytic
converter in display field 2.
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24-105
Significance of 3 digit indication in Display Group 030 1
1
1
Display fields 1 to 4
X Oxygen sensor control
0= inactive
1= active
X Operational readiness of oxygen sensor
0= inactive
1= active
X Condition of oxygen sensor heater
0= inactive
1= active

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

When indicated on display
Test requirements - Press buttons -0-, -4- and -3- to select "display group number 043" and press -Q-
button to confirm input.
Engine runs at 1900 - 2200 RPM
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- Press buttons -0-, -4- and -4- to select "display
group number 044" and press -Q- button to
confirm input.
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