engine AUDI A4 1996 B5 / 1.G AFC Engine On Board Diagnostic Multiport Fuel Injection Workshop Manual

01-225
Display group 037 (Sensor wheel learning value)
Notes:

In order to be able to monitor and/or record combustion misfiring, a sensor wheel is necessary. The flywheel (starter ring
gear) is used as the sensor wheel. The flywheel is checked for mechanical damage after each start, i.e. specified
tolerances must not be exceeded.
Small malfunctions in the flywheel (e.g. teeth worn) are compensated by learning values. If greater damage is recognized,
the malfunction "engine speed sensor wheel tooth error recognized" is stored in the DTC memory.
The sensor wheel is tested during a deceleration fuel shut-off in the engine speed range from 2200 -4000 RPM. In order to
get a result, the length of the deceleration fuel shut off must be approx. 10 sec.
Display shows
Display specified value
Designation/diagnosis
Basic setting 37
1 2 3 4 X X 1 = Sensor wheel condition and/or result
______ 2 = ________________________
______ 3 = ________________________
______ 4 = ________________________
Pa
ge 319 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-227
Display group 038 (Current data on combustion misfiring recognition)
Notes:

If the malfunctions "Combustion misfiring recognized" and "Cyl. X Combustion misfiring recognized"are stored in DTC
memory, display groups 031, 037, 038 and 039 are used to carry out a selective diagnosis.
Using display group 038, after a repair you can drive again in the load and engine speed range that was displayed in
display group 031 as the combustion misfiring range and evaluated again.
Display shows
Display/specified value
Designation/diagnosis
Basic setting 38
1 2 3 4 ... RPM 1 = Momentary engine speed
__._% 2 = Momentary engine load
0 - 255 3 = Combustion misfiring per 1000 RPM (1000th revolution interval)
X X X X X X 4 = Combustion misfiring including in this "1000th revolution interval"
Pa
ge 321 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-231
Display group 040 (Heating current of oxygen sensors in front of and behind three way catalytic converter) Display
shows Display specified value
Designation/diagnosis
Basic setting
40
1 2 3 4 At cold start, greater than 3 A after approx. 40 sec: 0.7 -
1.0 A 1 = Heating current, bank 1, heated oxygen
sensor 1
2 = Heating current, bank 2, heated oxygen
sensor 1
At cold start, greater than 3 A after approx. 80 sec: 1.2 -
1.4 A 3 = Heating current, bank 1, heated oxygen
sensor 2
4 = Heating current, bank 2, heated oxygen
sensor 2 Notes:

The current values specified apply only at when battery positive voltage (B+) is 12-14 volts display group 001, display
field 4. The heating of the heated oxygen sensors in front of the three way catalytic converter is switched on with the fuel pump
relay, i.e. immediately at engine start.
The heating of the heated oxygen sensors behind the three way catalytic converter is not switched on immediately at
engine start, but only when the calculated exhaust gas temperature in the three way catalytic converter exceeds 308 C
(586 F) display group 044, display field 2. In order to reach an exhaust gas temperature of 308 C (586 F) in the three
way catalytic converter after a cold start, the car must be driven about 20 sec. with an increased engine speed of 2500
RPM.
Pa
ge 325 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-232
Display group 041 (Voltage signal of oxygen sensors in front of and behind three way catalytic converter) Display
shows Display specified
value Designation/diagnosis
Basic setting
41
1 2 3 4 _.___ V 1 = Voltage signal, bank 1, heated oxygen sensor 1 display group 010, display
field 3 _.___ V 2 = Voltage signal, bank 2, heated oxygen sensor 1 display group 010, display
field 4 _.___ V 3 = Voltage signal, bank 1, heated oxygen sensor 2
_.___ V 4 = Voltage signal, bank 2, heated oxygen sensor 2 Notes on display field 3 and 4:

The voltage signals of bank 1 heated oxygen sensor 2 and/or bank 2 heated oxygen sensor 2 should not be evaluated
until at least 50 sec. after the oxygen sensor heating is switched on display group 040. With cold engine and ignition on, a voltage signal of 0.400 volts is displayed in all four display fields. With very hot engine
and ignition on, a signal of 0.000 volts is displayed in display field 3 and 4.
The voltage signal of the heated oxygen sensors behind the three way catalytic converter must lie between about 0.5 volts
and 0.6 volts with a three way catalytic converter with sufficient effect (conversion). During deceleration fuel shut off, the
voltage signal must be less than 0.1 volts constantly. During operation with wide open throttle enrichment, the voltage
signal must be greater than 0.6 volts.
If there is wide open throttle (signal voltage during wide open throttle enrichment greater than 0.6 volts) with a new three
way catalytic converter, distance driven less than 5,000 km (3,000 mi.) after a preceding deceleration fuel shut off (signal
Pa
ge 326 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-233
Display group 042 [Diagnostic conditions for diagnosis of the flank rise and/or flank fall time (response time) of the
voltage signal of heated oxygen sensors in front of three way catalytic converters]
Notes:

If the value of the oxygen sensor diagnosis is not set to "0" in display group 029, display field 1 during regeneration of the
readiness code and/or there is a malfunction in DTC memory that relates to the oxygen sensor, display group 042 can be
used to set up the diagnostic conditions (display fields 3 and 4) and the diagnostic result (display field 2) can be read.
If the diagnostic conditions are fulfilled, the Engine Control Module (ECM) checks the flank rise and/or flank fall time
(response time) of the voltage signal of the heated oxygen sensors in front of the three way catalytic converters at each
start, which is displayed each time display groups 032, 033, 034 and 43 are displayed.
The diagnostic conditions are only fulfilled during a trip of approx. 1-1/2 to 5 minutes at 80-100 km/h (50-63 mph) with
manual transmission in 4th or 5th gear, or automatic transmission selector lever in "D" position, preferably in 4th gear. If
the diagnostic conditions are fulfilled, diagnosis is active. In order to get a diagnosis result, you have to drive approx. 1-1/2
to 5 minutes under diagnostic conditions.
If a malfunction is stored in DTC memory, which affects diagnostic conditions 1 and 2, the diagnostic conditions can not be
achieved. In this case repair the malfunction "DTC memory, checking and erasing page 01
-13
.
If a malfunction is stored that involves the heated oxygen sensors in front of three way catalytic converters, the diagnostic
conditions can be achieved, but the diagnosis result can not be OK.
If the flank rise and flank fall time is recognized as OK during the first diagnosis, the diagnosis is discontinued. If the times
are recognized as not OK, the diagnosis of the flank rise and/or flank fall time is continued. If the diagnosis will be
repeated selectively or after an OK diagnosis, switch engine off and restart.
Pa
ge 328 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-234

Display
shows Display specified
value Designation/diagnosis
Basic setting
42
1 2 3 4 400 - 640 C
1 = Calculated exhaust gas temperature in front of three way catalytic converter
(calculated value inside control module)
X X X X X X X X 2 = Diagnosis status and/or result
X X X X X X X X 3 = Diagnostic conditions 1 for heated oxygen sensor diagnosis (response time of
heated oxygen sensor)
X X X X X X X X 4 = Diagnostic conditions 2 for heated oxygen sensor diagnosis (response time of
heated oxygen sensor)
Note on display field 2:
If after diagnosis all 8 displays are "1" and the engine is stopped and started again, display values 1 and 2 are reset to "0" and
values 3 to 8 remain at "1." If during the trip diagnostic conditions (display fields 3 and 4) are achieved, display values 1 and 2
are set to "1" (diagnosis active) and display values 3 to 8 are set to"0".
Value "0": Diagnosis not active and/or diagnosis not finished and/or diagnosis result not OK
Value "1": Diagnosis active and/or diagnosis finished (whether OK or not OK) and/or diagnosis result OK X
X
X
X
X
X
X
X
Meaning of 8-digit "Diagnosis status and/or result"

1 = Diagnosis, bank 1 active

2 = Diagnosis, bank 2 active

3 = Diagnosis, bank 1 finished

4 = Diagnosis result, bank 1, flank fall time
Pa
ge 329 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-235
Notes on display field 3 and 4:
Value "0" = Diagnosis condition not fulfilled.
Value "1" = Diagnosis condition fulfilled. X
X
X
X
X
X
X
X
Meaning of 8-digit "Diagnosis condition 1"

1 = Coolant temperature: 70 - 110 C ( display group 001)
2 = Engine load: 27 - 66% ( display group 003)
3 = Engine speed: 1800 - 2700 RPM ( display group 003)
4 = Fuel throughput after engine start
[only fulfilled after approx. 3 min. trip (no idle) after start]

5 = No fuel enrichment
(during diagnosis no enrichment can occur display group 019)
6 = Closed throttle position switch open ( display group 008)
7 = Oxygen sensor control, bank 2 active ( display group 008)
8 = Oxygen sensor control, bank 1 active ( display group 007)
Pa
ge 331 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-238
Display group 044 (Diagnostic conditions for three way catalytic converter diagnosis, bank 1 and bank 2)
Notes:

When the diagnostic conditions are fulfilled (display fields 3 and 4) by using the heated oxygen sensors in front of and
behind the three way catalytic converter, at each start the Engine Control Module (ECM) carries out a diagnosis of the
three way catalytic converter. During this diagnosis, the deterioration rate of the three way catalytic converter is
determined. The deterioration rate of the three way catalytic converter is displayed when display groups 035 and 036 are
displayed. However, this diagnosis is "cross-blocked." That means that before the three way catalytic converter diagnosis
can be evaluated, a result of the heated oxygen sensor diagnosis must be available to the Engine Control Module (ECM).
If a malfunction is stored in DTC memory that affects the heated oxygen sensors in front of or behind the three way
catalytic converter, the heated oxygen sensor diagnosis can not be carried out and the three way catalytic converter
diagnosis can not be evaluated.
If in display group 029, display field 1 the value of the three way catalytic converter diagnosis is not set to "0" during
regeneration of the readiness code, and/or a malfunction is stored in DTC memory that affects the three way catalytic
converter, display group 044 can be used to selectively call the diagnostic conditions (display fields 3 and 4).
If in display group 029, display field 1 the value of the three way catalytic converter diagnosis and the value of the heated
oxygen sensor diagnosis are not set to "0" during regeneration of the readiness code, display group 044, display field 1
can be used to determine whether the three way catalytic converter diagnosis has been carried out inside the engine
control module, but the value of the three way catalytic converter diagnosis under display group 029, display field 1 can
not be set to "0" because the heated oxygen sensor diagnosis has not been carried out.
Pa
ge 334 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-239

The diagnostic conditions are only achieved during a trip of approx. 1-1/2 to 5 minutes at 80-100 km/h (50-63 mph) with
manual transmission in 4th or 5th gear, or automatic transmission selector lever in "D" position, preferably in 4th gear.
However, the diagnostic conditions are only displayed 4 minutes after engine start, because until that time diagnosis is
prohibited. If the diagnostic conditions are fulfilled, diagnosis is active. Now, obtaining a diagnostic result requires a test
drive of approx. 1-1/2 to 5 min under the diagnostic conditions.
If a malfunction is stored in DTC memory that affects diagnostic conditions 1 and 2, the diagnostic conditions can not be
obtained. In this case repair the malfunction "DTC memory, checking and erasing," page 01
-13
. If a malfunction is
stored that involves the heated oxygen sensors in front of three way catalytic converter, the diagnostic conditions can be
achieved, but the diagnosis result can not be OK.
If the effect of the three way catalytic converter is recognized as OK during the first diagnosis, the diagnosis is
discontinued. If the effect (conversion) is recognized as not OK, the three way catalytic converter diagnosis is continued. If
the diagnosis will be repeated selectively and/or repeated after an OK diagnosis, stop the engine and start again.
Display
shows Display specified
value Designation/diagnosis
Basic setting
44
1 2 3 4 X _ X _ X X X X 1 = Diagnosis status

400 - 640 C
2 = Calculated temperature in three way catalytic converter (calculated value inside
the engine control module)
X X X X X X X X 3 = Diagnostic conditions 1 for three way catalytic converter diagnosis
X X X X X X X X 4 = Diagnostic conditions 2 for three way catalytic converter diagnosis
Pa
ge 335 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1

01-240
Notes on display field 1:
Display field 1 shows which diagnosis has been carried out or has not been carried out yet. If the three way catalytic converter
diagnosis is carried out inside the engine control module, but the heated oxygen sensor diagnosis has not been carried out
yet, the three way catalytic converter diagnosis is not evaluated and therefore the deterioration rate is not set in display
groups 035 and 036.
Value "0" = Diagnosis carried out
Value "1" = Diagnosis not carried out X

X

X
X
X
X
Meaning of 6-digit display

1 = Diagnosis flank fall time, bank 1, heated oxygen sensor 1

2 = Diagnosis flank rise time, bank 1, heated oxygen sensor 1

3 = Diagnosis flank fall time, bank 2, heated oxygen sensor 1

4 = Diagnosis flank rise time, bank 2, heated oxygen sensor 1

5 = ----------

6 = Three way catalytic converter diagnosis, bank 1

7 = ----------

8 = Three way catalytic converter diagnosis, bank 2
Pa
ge 336 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
(MFI
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1