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). 
Pa
ge 1 of 7 Heated Ox
yg
en Sensor 
(HO2S
) after Three Wa
y Catal
ytic Converter 
(TWC
), checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.24.13 
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
ge 5 of 7 Heated Ox
yg
en Sensor 
(HO2S
) after Three Wa
y Catal
ytic Converter 
(TWC
), checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.24.13