lock AUDI A4 1999 B5 / 1.G AFC Engine Heated Oxygen Sensor After Converter Checking Workshop Manual

24-53


Heated Oxygen Sensor
(HO2S) after Three Way
Catalytic Converter (TWC),
checking

Notes:

G130 = O2S behind three way catalytic
converter, bank 1
G131 = O2S behind three way catalytic
converter, bank 2
For functional check of O2S behind three way
catalytic converter -G130- or -G131- Repair
Group 01, Read measuring value block, display
group 041

- Disconnect connector for O2S behind three way
catalytic converter -G130- or- G131- (component
locations page 24
-1 ).

If there is continuity: - Using multimeter (Fluke 83 or equivalent) set for measuring resistance
( ), check for continuity (short circuit) between oxygen sensor
terminals 3 (GND wire) and 4 (signal wire).
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24-55

Oxygen sensor heater, checking

Notes:

Z29 = Oxygen Sensor (O2S) heater, bank 1
Z30 = Oxygen Sensor (O2S) heater, bank 2
For functional check of O2S heater -Z29- or -
Z30- Repair Group 01, Read measuring
value block, display group 040

- Disconnect heated oxygen sensor harness
connector (component locations page 24
-1 )

If the specified value is not obtained: - Switch multimeter (Fluke 83 or equivalent) to 20 volt range and connect
between terminals 1 (B+) and 2 (GND).
- Start engine and let idle.
Specified value: approx. 12 to 14 V
- Check oxygen sensor heater fuse.
- Check fuel pump relay page 24
-24
.

- Check wiring for continuity between terminal 1 and fuse in fuse holder
using wiring diagram, if necessary check terminal assignments.
Pa
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en Sensor
(HO2S
) after Three Wa
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ytic Converter
(TWC
), checkin
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11/22/2002 htt
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play?action=Goto&t
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pair&id=AUDI.B5.FU01.24.13