AUDI A4 1997 B5 / 1.G ATQ Engine Oxygen Sensor Control Checking
Manufacturer: AUDI, Model Year: 1997, Model line: A4, Model: AUDI A4 1997 B5 / 1.GPages: 63, PDF Size: 0.31 MB
Page 11 of 63

24-85
 Evaluation display group 033  Display field: 1 / 3  
Possible cause  
Corrective action  
Values in range: 
-10.0 to -25.0 %   
Oxygen sensor heating faulty- Check oxygen sensor heating   Page 
24
-116
 
or  
Values in range:   
Open circuit in wires between oxygen sensor 
and control module - Check primary voltage   Page 24
-89
10.0 to 25.0 %  
or  
Value does not fluctuate 
by at least 2 %   
Short circuit to Ground (GND) or B+ between 
oxygen sensor and control module - Check oxygen sensor wires bank 1   
Page 24
-90
 
- Check oxygen sensor wires bank 2   
Page 24
-91
 
  
 
False air in intake area- Check intake system for leaks and 
repair false air   Page 24
-64
 
  
 
Fuel pressure too low or too high- Check fuel pressure regulator   Page 
24
-30
 
  
 
Fuel return line is kinked or clogged- Check fuel return line.
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Page 12 of 63

24-86
      
- Press -C- button. 
     
-  Press buttons -0-, -3- and -2- to select "display 
group number 032" and press -Q- button to 
confirm input. System in Basic Setting 32  
1 
2 
3 
4
    
When indicated on display:  
-  Check oxygen sensor control in display fields 1 to 4:
  
Display fields  
  
1   2   3   4  
Display group 032: Oxygen sensor adaptation values before catalytic converter  
Display  
xx.x %  
xx.x %  
xx.x %  
xx.x %  
Indicated  
Oxygen sensor 
adaptation value 
Bank 1 at idle  
(additive)  Oxygen sensor adaptation 
value bank 1 at partial 
throttle 
(multiple)  Oxygen sensor 
adaptation value 
Bank 2 at idle  
(additive)  Oxygen sensor adaptation 
value bank 2 at partial 
throttle 
(multiple)  
Functional 
range  -25.0 to 25.0 %  
-25.0 to 25.0 %  
-25.0 to 25.0 %  
  -25.0 to 25.0 %  
  
Specified 
value  -10.0 to 10.0 %  
can fluctuate 
slightly  -10.0 to 10.0 %  
can fluctuate slightly  -10.0 to 10.0 %  
can fluctuate 
slightly  -10.0 to 10.0 %  
can fluctuate slightly  
Notes  
If specified value is not obtained   Page 24
-87
   
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Page 13 of 63

24-87
 Evaluation display group 032  Display field: 
1 / 3 or 2 / 4  
Possible cause  
Corrective action  
Oxygen sensor 
adaptation value in 
range: 
-10.0 to .-25.0 %   
Oil thinning- Oil change or perform swift country road 
test 
  
 High oil consumption  
  
 Mass Air Flow (MAF) sensor faulty- Mass Air Flow (MAF) sensor, checking 
 
 Page 24
-56
 
  
 
Evaporative Emission (EVAP) canister purge 
regulator valve remains stuck in open position - Check Evaporative Emission (EVAP) 
Canister Purge Regulator Valve   Page 24
-
128
 
  
 
Fuel pressure too high- Check fuel pressure regulator   Page 24
-
30
 
  
 
Fuel return line is kinked or clogged.- Check fuel return line.
  
 Fuel injector does not close- Check fuel injectors   Page 24
-36Pa
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Page 14 of 63

24-88
 Evaluation display group 032  Display field: 
1 / 3 or 2 / 4  
Possible cause  
Corrective action  
Oxygen sensor 
adaptation value in range: 
10.0 to 25.0 %   
False air in intake area- Check intake system for leaks and repair false 
air. 
 Page 24
-64
 . 
  
 
Fuel pressure too low- Check fuel pressure regulator   Page 24
-30
  
 
Mass Air Flow (MAF) sensor faulty- Mass Air Flow (MAF) sensor, checking 
 
 Page 24
-56
 
  
 
Oxygen sensor heating faulty
 Oxygen sensor faulty- Check oxygen sensor heating   Page 24
-116
  
 
Fuel injector does not open or opens 
only partially - Check fuel injectors   Page 24
-36
  
 
Evaporative Emission (EVAP) Canister 
Purge Regulator Valve sticks - Check Evaporative Emission (EVAP) Canister 
Purge Regulator Valve   Page 24
-128
 
  
 
Ignition coil or spark plug faulty- Check ignition coils   Page 28
-7
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Page 15 of 63

24-89
      
Checking primary voltage  
      Component location of harness connectors   
Overview of component locations, page   Page 
24
-5   
     
Note:  
     Coolant reservoir screws must be removed and 
coolant reservoir must be placed to side in order 
to access this harness connector. The coolant 
hoses can remain connected. 
     
Test requirement:  
     
Fuse for oxygen sensor are OK 
     
-  Disconnect 4-pin harness connector leading to 
respective oxygen sensor. 
    
If specified value is not obtained:  -  Connect multimeter between terminal 3 and 4 for voltage 
measurement. 
-  Switch ignition on.
 
Specification: 0.400 to 0.500 V
-  Switch ignition off.
- 
Check oxygen sensor wires   Bank 1, page   Page 24
-90
 or   Bank Pa
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Page 16 of 63

2, page   Page 24
-91
 . 
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Page 17 of 63

24-90
      
Check oxygen sensor wires bank 1 for Heated 
Oxygen Sensor (HO2S) 2 -G39-.  
      Component location of harness connectors   
Overview of component locations, page   Page 
24
-5   
     
-  Disconnect black 4-pin harness connector to 
bank 1 Heated Oxygen Sensor (HO2S) -G39-. 
     
-  Connect VAG1598/31 test box at wiring harness 
to ECM, do not connect ECM   Page 24
-17
 . 
    
-  Check the following wire connections for open circuit.Harness connector  
Terminal  
VAG1598/31 test box  
Socket  
3   51  
4   70  
-  Repair open circuit if necessary.
-  Check wires to each other for short circuit.Harness connector  
Terminal  
VAG1598/31 test box  
Socket  
4   51  
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Page 18 of 63

24-91
 
    
If no malfunctions are found in wires:  
Check oxygen sensor wires bank 2 for Heated Oxygen Sensor 
(HO2S) 2 -G108-.  
Component location of harness connectors   Overview of component 
locations, page   Page 24
-5    -  Check shielded wire for short circuit to sensor wires.
Harness connector  
Terminal  
VAG1598/31 test box  
Socket  
3   32  
4   32  
-  Replace Engine Control Module (ECM)   Page 24
-21
 .
-  Disconnect black 4-pin harness connector to bank 2 Heated Oxygen 
Sensor (HO2S) 2 -G108-. 
-  Connect VAG1598/31 test box at wiring harness to ECM, do not 
connect ECM   Page 24
-17
 . 
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Page 19 of 63

24-92
 
    
If no malfunctions are found in wires:  -  Check the following wire connections for open circuit.Harness connector  
Terminal  
VAG1598/31 test box  
Socket  
3   12  
4   13  
-  Repair open circuit if necessary.
-  Check wires to each other for short circuit.Harness connector  
Terminal  
VAG1598/31 test box  
Socket  
4   12  
-  Check shielded wire for short circuit to sensor wires.Harness connector  
Terminal  
VAG1598/31 test box  
Socket  
3   32  
4   32  
-  Replace Engine Control Module (ECM)   Page 24
-21
 .
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Page 20 of 63

24-93
      
Oxygen sensor aging (oxygen sensor 
before catalytic converter), checking
 
     
Special Tools and Equipment  
    
VAG1788/10 RPM adjuster
    
Test requirement: 
VAS5051 with VAG5051/1
   orVAG1551 with VAG1551/3BCoolant temperature at least 80  C   Display group 4, display field 3
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