Page 1 of 7
24-45
 
     
Oxygen Sensor (O2S) control, 
checking (before three way 
catalytic converter) 
     
Note:  
     
G39 = Heated Oxygen Sensor (HO2S), bank 
1 
     G108 = Heated Oxygen Sensor (HO2S) 2, bank 
2 
     
-  Read measuring value block using VAG 1551 
scan tool until display shows "Read measuring 
value block 1" (display group 001)   Repair 
Group 01. 
Read measuring value block 1 1 2 3 4 
    
Indicated on display  
Note:  
Continue with the test only if the value in display field 1 (engine coolant 
temperature) is at least 80 C (176 F). - Press -C- button.
-  Press buttons -0-, -1- and -0- to input display group 010.
-  Press -Q- button to confirm input.
Read measuring value block 10 
    
Indicated on display  
Pa
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11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.24.11 
         
        
        
     
        
        Page 3 of 7
24-46
       If a constant sensor voltage of 0.000V is 
displayed, there is a short to Ground (GND).  
     
-  Check DTC memory   Repair Group 01.      If sensor voltage is constant between 0.350 and 
0.450 volts, the signal is interrupted:  
     
-  Check DTC memory   page 01
-13
 .
      If sensor voltage is a constant 2.550 volts, there 
is a short to battery positive voltage (B+):  
     
-  Check DTC memory   page 01
-13
 .
     
-  If sensor voltage is a constant 0.0 to 0.3 volts, 
the oxygen sensor measures a lean mixture: 
     
-  Check DTC memory   page 01
-13
 .
     
-  If sensor voltage is a constant 0.6 to 0.9 volts, 
the oxygen sensor measures a rich mixture: 
     
-  Check DTC memory   page 01
-13
 .
     
- Press -C- button.Read measuring value block 
Q
    
- Indicated on display
Pa
ge 3 of 7 Ox
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(O2S
) control, checkin
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ytic converter
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.24.11 
         
        
        
     
        
        Page 7 of 7
24-48
      
-  Press buttons -0-, -0- and -5- to input display 
group number 005 for bank 1, or press buttons -
0-, -0- and -6- to input display group number 006 
for bank 2. 
     
-  Press -Q- button to confirm input.Read measuring value block 5 -4.6% 0.7% 0 % 0 %
    
Indicated on display (example)  
Note:  
If necessary, display group 005 (bank 1) or 006 (bank 2) for 
troubleshooting can be read using "Basic Setting" function 04 and then 
printed out   page 01
-150
 , Basic Setting. By selecting this function 
(among other things) the evaporative emissions factor is not included. 
Pa
ge 7 of 7 Ox
yg
en Sensor 
(O2S
) control, checkin
g (before three wa
y catal
ytic converter
)
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU01.24.11