1995 AUDI A4 sensor

01-192

Display
fields Display on VAG 1551 scan tool
Malfunction cause
Malfunction repair
3/4
Constant value between 0.350 -
0.450 V Open circuit in:
Heated Oxygen Sensor (HO2S) -G39-
wiring Engine Control Module (ECM) -J192-- Check -G39- page
24
-49


Constant 0.000 V Short to ground in:
Heated Oxygen Sensor (HO2S) -G39-
wiring Engine Control Module (ECM) -J192-- Check -G39- page
24
-49


Notes on display field 4:
The display value at times must drop below 0.3 V
and exceed 0.6 V. Display values less than 0.40
V indicate lean condition; greater than 0.40 V
indicate rich condition.

HO2S voltage U (mV) vs. Lambda ( ) A - HO2S voltage (mV) high
Rich mixture (fuel excess or lack of air)
High CO value
B - Oxygen sensor probes voltage (mV) low
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If there is engine damage (oil burning because of faulty piston)
If a knock sensor malfunction is recognized in DTC memory, ignition map switching is blocked.
Notes on display field 4:
Knock control is active starting at an engine load greater than 40% Display groups 013 and/or 014. The ignition timing point retarding values are only used when knock control is "active."
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01-196
Display groups 013 and 014
Notes on display fields 2, 3 and 4:
Knock control is active starting at an engine load greater than 40%. If the engine load exceeds 40%, the current ignition timing
point retarding value is displayed; if the engine load drops below 40%, the last values used are displayed constantly.
If there is audible knocking without recognizable retarding of the ignition timing point, the engine speed should be increased
over 3500 RPM for 5 seconds to initiate the knock sensor malfunction recognition (On Board Diagnostic).
If an ignition timing point retarding value of one cylinder deviates from the others, the following malfunctions are possible:

Loose subassemblies
Corrosion on the harness connector
Engine damage (e.g. oil combustion with faulty piston)
If there are high ignition timing point retarding values on all cylinders of bank 1 or bank 2, the following malfunctions are
possible:
Corrosion on the harness connector display groups 015 and 016 Knock sensor tightening torque, 20 Nm (14 ft lb), not OK
Open circuit display groups 015 and 016 Knock sensor faulty
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01-197
Display group 015 Display shows
Specified display value
Designation
Basic setting 15
1 2 3 4 ___ RPM 1 = Momentary engine speed display group 003, display field 1 _._V 2 = Knock sensor signal (cylinder 1)
_._V 3 = Knock sensor signal (cylinder 2)
_._V 4 = Knock sensor signal (cylinder 3) Display group 016 Display shows
Specified display value
Designation
Basic setting 16
1 2 3 4 ___ RPM 1 = Momentary engine speed display group 003, display field 1 _._ V 2 = Knock sensor signal (cylinder 4)
_._ V 3 = Knock sensor signal (cylinder 5)
_._ V 4 = Knock sensor signal (cylinder 6)
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01-198
Display groups 015 and 016
Notes on display fields 2, 3 and 4:
If there is a difference of more than a factor of 3 between the lowest and the highest knock sensor signal in one display group,
the following malfunction is possible:

Corrosion on the harness connector
If there are differences of more than 50% in knock sensor signal between display group 015 (cylinders 1 to 3) and display
group 016 (cylinders 4 to 6), the following malfunctions are possible:
Corrosion on the harness connector
Open circuit
Knock sensor faulty
If no malfunctions are found during the electrical testing of the knock sensor, the wiring and the connections, the engine
should be checked for loose subassemblies or engine damage (e.g. oil burning due to faulty piston) Display groups 013
and/or 014.
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01-200

Display shows
Specified display value
Designation
Basic setting 17
1 2 3 4 0 - 1 1 = Timer 1 (final value = 1)
0 - 225 2 = Timer 2 (final value = 48 or 160)
30% - 60% 3 = Momentary engine load

0C - 255C
4 = Exhaust gas recirculation temperature (EGR temperature sensor -G98-)
Notes on display fields 1 and 2:

In display fields 1 and 2, the timers are displayed. The final value of timer 2 is "48" or "160". The final values "48" and
"160" are reading times ("48" = reading time 1; "160" = reading time 2).
If the diagnostic conditions are fulfilled, the timers are incremented, outside the diagnostic conditions they are
decremented.
Counter 1 is incremented by "1" as soon as counter 2 reaches the value "255." If the value 255 is reached, counter 2 goes
back to "0" and starts to increment again up to "48" (reading time 1).
If reading time 1 has been reached, the Engine Control Module (ECM) -J192- checks the EGR temperature (display field
4). If the EGR temperature is greater than 50 C (122 F), the diagnosis is OK and the diagnostic program is discontinued.
If the EGR temperature during reading time 1 is less than 50 C (122 F),counter 2 counts up to "160"(reading time 2). When reading time 2 is reached, the -J192- checks the EGR temperature (display field 4) again. If the EGR temperature is
now greater than 50 C (122 F), the diagnosis is OK and the diagnostic program will be discontinued. If the EGR
temperature is again less than 50 C (122 F), the EGR flow test is carried out again.
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01-202
Display group 019 Display shows
Specified display value
Designation/diagnose
Basic setting 19
1 2 3 4 At idle: 1.5 - 3.5% 1 = Momentary engine power (internal computation value)
At 2500 RPM:
6.5 - 9.5%
At idle:
3.0 - 5.5 g/s 2 = Intake air quantity (via mass air flow sensor)
At 2500 RPM:
9.5 - 13.5 g/s
___ km/h 3 = Momentary vehicle speed display group 003, display field 4 _._ m/s 4 = Fuel injection time (average of all cylinders) Note on display field 1:
The momentary engine power is a control module-internal calculated value that is calculated from the amount of air taken in
under normal conditions (air pressure 1013 mbar, air temperature 20 C or 68 F).
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01-203
Display groups 020 and 021
Note:
Display groups 020 and 021 are only considered in vehicles with Secondary Air Injection (AIR) system. Display shows
Display/specified value
Designation/diagnose
Basic setting 20
1 2 3 4 0% 1 = Lean time of bank 1, HO2S 1 voltage signal
0% 2 = Lean time of bank 2, HO2S 1 voltage signal
69% 3 = Diagnosis limit value
00000000 4 = Diagnosis condition and/or result Display group 021 Display shows
Display/specified value
Designation/diagnose
Basic setting 21
1 2 3 4 0.0% 1 = Oxygen sensor control, bank 1 richens
0.0% 1 = Oxygen sensor control, bank 2 richens
14.0% 3 = Diagnosis limit value
00000000 4 = Diagnosis condition and/or result
Pa
ge 286 of 366 On Board Dia
gnostic
(OBD
) - Multi
port Fuel In
jection
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)
11/22/2002 htt
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.01.1