tow AUDI A4 1998 B5 / 1.G AHA Engine On Board Diagnostic Workshop Manual

01-66

Display fields 7 + 8
Possible malfunction cause
Corrective action
less than 77

Mixture too rich-oxygen sensor control
adjusts toward too lean
Oxygen sensor control at limit
Too much fuel vapor from EVAP canister
Fuel pressure regulator faulty, or hose
disconnected - Check HO2S and O2S control before TWC
page 24
-22

- Check fuel pressure regulator page 24
-111
greater than 179

Mixture too lean-oxygen sensor control
adjusts toward too rich
Intake air leaks ("false air")
Fuel injector(s) faulty
Oxygen sensor control at limit- Check HO2S and O2S control before TWC
page 24
-22

- Check intake air system for leaks page 24
-
126

- Check fuel injector(s) page 24
-102


Secondary air system
Output Diagnostic Test Mode (DTM), page 01
-
51
and
Repair Manual, 2.8 Liter V6 5V Engine
Mechanical, Repair Group 26 - Check secondary air system
128

Too little fuel
Oxygen sensor control blocked- Check fuel level in tank
- Check HO2S and O2S control before TWC
page 24
-22

Pa
ge 91 of 97 On Board Dia
gnostic
(OBD
)
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.FU03.01.1