1998 AUDI A4 check engine

01-100

Work step 8: Diagnostic of oxygen sensor
control system

Test requirement:

Engine continues to run at 2600 RPM.

Display on VAS5051:
-
Press button to change into display group 037.- Check specified value in display field -4-.
Pa
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01-104


Display fields

1 2 3 4
Display group 043: Oxygen sensor aging diagnostic, oxygen sensor behind catalytic converter (bank 1)
Display xxxx/min
xxx C
x.xxx V
---
Indicated Engine speed
(RPM) Exhaust
temperature Oxygen sensor voltage
Bank 2, sensor 1 Diagnostic condition
Functional
range Test OFF
Test ON
B1-S2 OK
B1-S2 not OK
Specified
value 2600 RPM larger than 350
C
0.100 to 0.950 volts B1-S2 OK
Note



If "B1-S2 not OK" is displayed: Check
DTC memory Page 01
-12

If specified value B1-S2 OK" is obtained:

- Perform next work step.
Pa
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01-105

Work step 10: Diagnostic of catalytic
converter

Test requirement:

Engine continues to run at 2600 RPM.

Display on VAS5051:
Note:
Catalytic converter diagnostic lasts approx. 60 seconds. -
Press button 3 times to change into display group 046.- Check specified values in display fields -2- and -4-.
Pa
ge 34 of 43 Readiness code11/22/2002 htt
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01-106


Display fields

1 2 3 4
Display group 046: Diagnostic of catalytic converter (bank 1)
Display xxxx/min
xxx C
x.xx
---
Indicated Engine
speed
(RPM) Exhaust temperature Measurement
Catalytic
converter -
conversion Diagnostic condition
Functional
range 0 to 8 Test OFF
Test ON
Cat B1 OK
Cat B1 not OK
Specified
value 2600 RPM
550 to 700 C
Larger than 1.0 Cat B1 OK
Note

As long as the exhaust temperature
is not within the specified range, the
test will not be initiated. If necessary,
increase or decrease RPM
If "Cat B1 not OK" is displayed:
Check DTC memory Page 01
-
12
. If no DTCs are stored,
replace catalytic converter.
If specified value "Cat B1 OK" is obtained:

- Perform next work step.
Pa
ge 35 of 43 Readiness code11/22/2002 htt
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e=re
pair&id=AUDI.B5.FU07.01.7

01-112


Display fields

1 2 3 4
Display group 077: Secondary Air Injection (AIR) system diagnostic (Bank 1)
Display xxxx/min xx.x
g/s xx %
---
Indicated Engine speed
(RPM) Air
mass Relative air mass bank 1,
Secondary Air Injection (AIR)
system Diagnostic condition
Functional
range
Test OFF
Test ON
System OK
System not OK
Aborted
Specified
value FWD: 740 to
860 RPM
AWD: 760 to
880 RPM 2 to 5
g/s more than -20 % System OK
Note


If "System not OK" is displayed:
Check DTC memory Page 01
-12

If specified value "Syst. OK" is obtained:

Pa
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