fuel AUDI A8 2000 D2 / 1.G ATQ Engine Oxygen Sensor Control Checking
Page 11 of 63
24-85
Evaluation display group 033 Display field: 1 / 3
Possible cause
Corrective action
Values in range:
-10.0 to -25.0 %
Oxygen sensor heating faulty- Check oxygen sensor heating Page
24
-116
or
Values in range:
Open circuit in wires between oxygen sensor
and control module - Check primary voltage Page 24
-89
10.0 to 25.0 %
or
Value does not fluctuate
by at least 2 %
Short circuit to Ground (GND) or B+ between
oxygen sensor and control module - Check oxygen sensor wires bank 1
Page 24
-90
- Check oxygen sensor wires bank 2
Page 24
-91
False air in intake area- Check intake system for leaks and
repair false air Page 24
-64
Fuel pressure too low or too high- Check fuel pressure regulator Page
24
-30
Fuel return line is kinked or clogged- Check fuel return line.
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11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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Page 13 of 63
24-87
Evaluation display group 032 Display field:
1 / 3 or 2 / 4
Possible cause
Corrective action
Oxygen sensor
adaptation value in
range:
-10.0 to .-25.0 %
Oil thinning- Oil change or perform swift country road
test
High oil consumption
Mass Air Flow (MAF) sensor faulty- Mass Air Flow (MAF) sensor, checking
Page 24
-56
Evaporative Emission (EVAP) canister purge
regulator valve remains stuck in open position - Check Evaporative Emission (EVAP)
Canister Purge Regulator Valve Page 24
-
128
Fuel pressure too high- Check fuel pressure regulator Page 24
-
30
Fuel return line is kinked or clogged.- Check fuel return line.
Fuel injector does not close- Check fuel injectors Page 24
-36Pa
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11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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pair&id=AUDI.B5.FU05.24.3
Page 14 of 63
24-88
Evaluation display group 032 Display field:
1 / 3 or 2 / 4
Possible cause
Corrective action
Oxygen sensor
adaptation value in range:
10.0 to 25.0 %
False air in intake area- Check intake system for leaks and repair false
air.
Page 24
-64
.
Fuel pressure too low- Check fuel pressure regulator Page 24
-30
Mass Air Flow (MAF) sensor faulty- Mass Air Flow (MAF) sensor, checking
Page 24
-56
Oxygen sensor heating faulty
Oxygen sensor faulty- Check oxygen sensor heating Page 24
-116
Fuel injector does not open or opens
only partially - Check fuel injectors Page 24
-36
Evaporative Emission (EVAP) Canister
Purge Regulator Valve sticks - Check Evaporative Emission (EVAP) Canister
Purge Regulator Valve Page 24
-128
Ignition coil or spark plug faulty- Check ignition coils Page 28
-7
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11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.24.3
Page 56 of 63
24-121
Checking voltage supply for oxygen sensor
heating
Test requirement:
Fuse for oxygen sensor heating OK
Electrical Wiring Diagrams, Troubleshooting &
Component Locations binder
Fuel Pump (FP) OK, checking Page 24
-
49
.
Component location of harness connectors
Overview of component locations, page Page
24
-5
- Disconnect 4-pin harness connector leading to
respective oxygen sensor.
- Connect multimeter between terminal 1 and 2 for voltage
measurement.
Pa
ge 56 of 63 Ox
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11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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pair&id=AUDI.B5.FU05.24.3
Page 59 of 63
24-123
If there is no voltage again:
- Check wire connection from terminal 1 to Fuel
Pump (FP) relay via fuse for open circuit.
Electrical Wiring Diagrams, Troubleshooting &
Component Locations binder If voltage supply is OK:
If there is no voltage: - Connect multimeter for voltage measurement as follows:Harness connector
Terminal
Measure
to
2 (Ground -GND- activation of Engine Control Module -
ECM-) B+
- Start engine.
Specification: approx. battery voltage, possibly fluctuating
- Switch ignition off.
- Connect VAG1598/31 test box at wiring harness to ECM, do not
connect ECM Page 24
-17
.
Pa
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11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.24.3