1998 AUDI A4 display

24-80
Evaluation display group 033 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
-80


Open circuit in wire 3 between oxygen sensor
and control module
constant about
0.200 V Oxygen sensor faulty- Replace oxygen sensor
larger than
1.100 V Short circuit to B+ in wire 4 between oxygen
sensor and control module - Check oxygen sensor wiring, oxygen sensor
before catalytic converter Page 24
-81

smaller than
0.150 V
Short circuit to Ground (GND) in wire 4 between
oxygen sensor and control module

Checking primary voltage

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 -2- (black) to Heated Oxygen Sensor
(HO2S) -G39- before catalytic converter.
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24-84

Test sequence

- Connect VAS5051 tester or VAG1551 scan tool
and select control module for engine electronics
using "address word" 01 Page 01
-10
. Engine
must run at idle.
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
Enter 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
1800 and 2200 RPM.
- Check specified value in display field 4:
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24-85


Display fields

1 2 3 4
Display group 034: Diagnostic oxygen sensor aging
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

Test OFF
Test ON
B1-S2 OK
B1-S2 not OK
Specified
value 1800 to 2200
RPM more than 350 C
0.0 to 1.0 s B1-S2 OK
Note


If specified value is not obtained Continuation, Page 24
-
86

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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24-86

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

- Road test vehicle in order to free oxygen sensor
of possible residue and repeat test.
If specified value in display field 3 and 4 is not
obtained, even after road test:

- Replace Heated Oxygen Sensor (HO2S) -
G39-.
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24-89

Test requirements:

Road test performed and DTC memory
erased.
Coolant Temperature at least 80 C.

Test sequence

- Connect VAS5051 tester or VAG1551 scan tool
and select control module for engine electronics
using "address word" 01 Page 01
-10
. Engine
must run at idle.
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
Enter 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.
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24-90

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 350 C. - Press -C- button.
- Use VAG1788/10 RPM adjuster to adjust engine speed to between
1800 and 2200 RPM.
Basic Setting
Q
Enter 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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Display fields

1 2 3 4
Display group 030: Oxygen sensor status with engine at idle
Display X X X
X X X

Indicated Oxygen sensor status, bank 1, sensor 1
Oxygen sensor status Bank 2, sensor 1

Functional range 0 = off
1 = on 0 = off
1 = on

Specified value 1 1 1
1 1 0

Note
If specified value is not obtained Page 24
-99

Significance of 3 digit indications in display group 030 X
X
X
Display fields 1 and 2
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 heater: 0= not active; 1 = active
Note:

Oxygen sensor control of oxygen sensor behind catalytic converter (B1-S2) is not active without engine load.
The first position of the 3 digit indication (heating) fluctuates between 0 and 1.
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24-92

Checking oxygen sensor control behind
catalytic converter

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

When indicated on display
- Press buttons -0-, -3- and -7- to select "display group number 037" and
press -Q- button to confirm input.
System in basic setting 37
1
2
3
4

When indicated on display
- Check oxygen sensor voltage in display field 2.
- Check dwell time of oxygen sensor control before catalytic converter in
display field 3 and diagnostic result in display field 4.
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p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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pair&id=AUDI.B5.FU06.24.2