AUDI A4 1996 B5 / 1.G APB Engine Oxygen Sensor Control Checking Repair Manual
Page 51 of 61
24-123
       If Specified value is obtained:  
     
-  Replace relevant oxygen sensor.
     
Checking oxygen sensor wiring for Heated 
Oxygen Sensor (HO2S) -G39  
      Component location of 4-pin harness connector 
of oxygen sensor   Page 24
-5 .  
     
-  Disconnect 4-pin connector (black) for Heated 
Oxygen Sensor (HO2S) -G39. 
     
-  Connect VAG1598/31 test box to wiring harness 
for engine control module. Do not connect to 
engine control module itself   Page 24
-20
 . 
    
 Electrical Wiring Diagrams, Troubleshooting & Component Locations    -  Check following wiring connections for open circuits:
Connector on wiring harness, 
socket  
VAG1598/31 test box socket 
  
3   51  
4   70  
   Resistance in wiring: max. 1.5 Ohm
Pa
ge 51 of 61 Ox
yg
en sensor control, 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.FU04.24.2 
Page 52 of 61
24-124
 
    
 Electrical Wiring Diagrams, Troubleshooting & Component Locations   
 Electrical Wiring Diagrams, Troubleshooting & Component Locations   
If no malfunction is identified in the wiring:  -  Check wiring also on 4-pin harness connector for short circuits to each 
other. 
Connector on wiring harness, 
socket  
VAG1598/31 test box socket 
  
4   51  
   Specified value: infinite ohms (open circuit)-  Check shielded wire for short circuit to sensor wiring.
Connector on wiring harness, 
socket  
VAG1598/31 test box socket 
  
4   32  
3   32  
   Specified value: infinite ohms(open circuit)-  Replace Motronic Engine Control Module (ECM) -J220   Page 24
-24
 .
Pa
ge 52 of 61 Ox
yg
en sensor control, 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.FU04.24.2 
Page 53 of 61
24-125
      
Checking wiring for Oxygen Sensor (O2S) 
Behind Three Way Catalytic Converter (TWC) 
-G130  
      Component location of 4-pin harness connector 
of oxygen sensor   Page 24
-5 .  
     
-  Disconnect 4-pin connector (black) for Oxygen 
Sensor (O2S) Behind Three Way Catalytic 
Converter (TWC) -G130. 
     
-  Connect VAG1598/31 test box to wiring harness 
for engine control module. Do not connect to the 
engine control module itself   Page 24
-20
 . 
    
 Electrical Wiring Diagrams, Troubleshooting & Component Locations    -  Check following wiring connections for open circuits:
Connector on wiring harness, 
socket  
VAG1598/31 test box socket 
  
3   68  
4   69  
   Resistance in wiring: max. 1.5 ohm
Pa
ge 53 of 61 Ox
yg
en sensor control, 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.FU04.24.2 
Page 54 of 61
24-126
 
    
 Electrical Wiring Diagrams, Troubleshooting & Component Locations   
 Electrical Wiring Diagrams, Troubleshooting & Component Locations   
If no malfunction is identified in the wiring:  -  Check wiring also on 4-pin harness connector for short circuits to each 
other. 
Connector on wiring harness, 
socket  
VAG1598/31 test box socket 
  
4   68  
   Specified value: infinite ohms (open circuit)-  Check shielded wire for short circuit to sensor wiring.
Connector on wiring harness, 
socket  
VAG1598/31 test box socket 
  
4   32  
3   32  
   Specified value: infinite ohms (open circuit)-  Replace Motronic Engine Control Module (ECM) -J220   Page 24
-24
 .
Pa
ge 54 of 61 Ox
yg
en sensor control, 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.FU04.24.2 
Page 55 of 61
24-127
      
Checking wiring for Heated Oxygen Sensor 
(HO2S) 2 -G108  
      Component location of 4-pin harness connector 
of oxygen sensor   Page 24
-5 .  
     
-  Disconnect 4-pin connector (black) for Heated 
Oxygen Sensor (HO2S) 2 -G108. 
     
-  Connect VAG1598/31 test box to wiring harness 
for engine control module. Do not connect to the 
engine control module itself   Page 24
-20
 . 
    
 Electrical Wiring Diagrams, Troubleshooting & Component Locations    -  Check following wiring connections for open circuits:
Connector on wiring harness, 
socket  
VAG1598/31 test box socket 
  
3   12  
4   13  
   Resistance in wiring: max. 1.5 ohm
Pa
ge 55 of 61 Ox
yg
en sensor control, 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.FU04.24.2 
Page 56 of 61
24-128
 
    
 Electrical Wiring Diagrams, Troubleshooting & Component Locations   
 Electrical Wiring Diagrams, Troubleshooting & Component Locations   
If no malfunction is identified in the wiring:  -  Check wiring also on 4-pin harness connector for short circuits to each 
other. 
Connector on wiring harness, 
socket  
VAG1598/31 test box socket 
  
4   12  
   Specified value: infinite ohms (open circuit)-  Check shielded wire for short circuit to sensor wiring.
Connector on wiring harness, 
socket  
VAG1598/31 test box socket 
  
4   32  
3   32  
   Specified value: infinite ohms (open circuit)-  Replace Motronic Engine Control Module (ECM) -J220   Page 24
-24
 .
Pa
ge 56 of 61 Ox
yg
en sensor control, 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.FU04.24.2 
Page 57 of 61
24-129
      
Checking wiring for Oxygen Sensor (O2S) 2 
Behind Three Way Catalytic Converter (TWC) 
-G131  
      Component location of 4-pin harness connector 
of oxygen sensor   Page 24
-5 .  
     
-  Disconnect 4-pin connector for Oxygen Sensor 
(O2S) 2 Behind Three Way Catalytic Converter 
(TWC) -G131 
     
-  Connect VAG1598/31 test box to wiring harness 
for engine control module. Do not connect to the 
engine control module itself   Page 24
-20
 . 
    
 Electrical Wiring Diagrams, Troubleshooting & Component Locations    -  Check following wiring connections for open circuits:
Connector on wiring harness, 
socket  
VAG1598/31 test box socket 
  
3   10  
4   11  
   Resistance in wiring: max. 1.5 ohm
Pa
ge 57 of 61 Ox
yg
en sensor control, 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.FU04.24.2 
Page 58 of 61
24-130
 
    
 Electrical Wiring Diagrams, Troubleshooting & Component Locations   
 Electrical Wiring Diagrams, Troubleshooting & Component Locations   
If no malfunctions are identified in the wiring:  -  Check wiring also on 4-pin harness connector for short circuits to each 
other. 
Connector on wiring harness, 
socket  
VAG1598/31 test box socket 
  
4   10  
   Specified value: infinite ohms (open circuit)-  Check shielded wire for short circuit to sensor wiring.
Connector on wiring harness, 
socket  
VAG1598/31 test box socket 
  
4   32  
3   32  
   Specified value: infinite ohms (open circuit)-  Replace Motronic Engine Control Module (ECM) -J220   Page 24
-24
 .
Pa
ge 58 of 61 Ox
yg
en sensor control, 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.FU04.24.2 
Page 59 of 61
24-131
       If no malfunction can be identified in the wiring:  
     
-  Replace Motronic Engine Control Module (ECM) 
-J220  Page 24
-24
 . 
     
-  Display readiness code   Page 01
-101
 . The 
readiness code must be generated if the DTC 
memory was erased   Page 01
-105
 . 
Pa
ge 59 of 61 Ox
yg
en sensor control, 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.FU04.24.2 
Page 60 of 61
24-132
      
Oxygen sensors, removing and 
installing
 
     
Removing  
     
-  Disconnect harness connector of particular 
oxygen sensor before catalytic converter for 
bank 1 and bank 2 (component location   Page 
24
-5 ). 
     
-  Disconnect harness connector of particular 
oxygen sensor behind catalytic converter for 
bank 1 and bank 2 (component location   Page 
24
-5 ). 
     
-  Remove particular oxygen sensor with 3337/7 
special tool. 
     
-  Lower transmission, in order to remove oxygen 
sensors behind catalytic converter. 
     
       Repair Manual, 6 Spd. Manual Transmission 
01E, Repair Group 34, Transmission removing and installing.
   
Pa
ge 60 of 61 Ox
yg
en sensor control, 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.FU04.24.2