engine AUDI A4 1998 B5 / 1.G APB Engine Oxygen Sensor Control Checking Owner's Manual
[x] Cancel search | Manufacturer: AUDI, Model Year: 1998, Model line: A4, Model: AUDI A4 1998 B5 / 1.GPages: 61, PDF Size: 0.27 MB
Page 46 of 61

24-118
      
-  Operate starter briefly. 
     
   Specified value: approx. battery voltage
      If there is still no voltage reading:  
     
-  Check for open circuit and/or short circuit in 
wiring between fuel pump relay and socket 1 on 
the relevant oxygen sensor connector (on wiring 
harness) via fuse. 
     
       Electrical Wiring Diagrams, Troubleshooting & 
Component Locations         If the voltage supply is OK:  
    
-  Connect hand-held multimeter (voltage measurement range) between 
socket 2 (switched Ground (GND) connection from engine control 
module) and B+ terminal using test leads from VAG1594 connector test 
kit. 
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Page 47 of 61

24-119
      
- Start engine.
     
   Specified value: approx. battery voltage 
(fluctuating) 
     
Note:  
     At certain points in the operating range the 
engine control module continuously "switches" 
the Ground (GND) connection to the oxygen 
sensor heater. That means, it repeatedly 
connects and disconnects the Ground (GND) 
connection at these points. For this reason the 
voltage reading on the tester may fluctuate. 
     
-  Switch ignition off.
      If there is no voltage reading:  
     
-  Connect VAG1598/31 test box to wiring harness 
for engine control module. Do not connect to the 
engine control module itself   Page 24
-20
 . 
    
-  Check for open circuits in the following wiring connection:
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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
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en sensor control, checkin
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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.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
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en sensor control, checkin
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11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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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