wiring AUDI A6 1997 C5 / 2.G ATQ Engine Additional Signals Testing Workshop Manual
[x] Cancel search | Manufacturer: AUDI, Model Year: 1997, Model line: A6, Model: AUDI A6 1997 C5 / 2.GPages: 44, PDF Size: 0.19 MB
Page 2 of 44

24-166
      
Engine speed signal, checking
 
     
Note:  
     The engine speed signal is output at terminal 37 
of the Engine Control Module (ECM). The signal 
is used, among other things, for RPM display in 
the instrument cluster. 
     
-  Connect VAG1598/31 test box at wiring harness 
to ECM, do not connect ECM   Page 24
-17
 . 
     
-  Check the following wire connection for open 
circuit and short circuit to Ground (GND) and B+:
     
Test box  
VAG1598/31  
Socket  
Instrument cluster  
  
Terminal  
37    Electrical Wiring Diagrams, 
Troubleshooting & Component 
Locations binder   
     
-  Repair open circuit or short circuit if 
necessary. 
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Page 3 of 44

24-167
      
Consumption signal for on board 
computer, checking
 
     
Notes:  
     
The consumption signal is calculated by the 
ECM from the injection time and directed to the 
on board computer via terminal 81 of the ECM. 
     Consumption signal, checking
     
       Electrical Wiring Diagrams, Troubleshooting & 
Component Locations binder   
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Page 4 of 44

24-168
      
Vehicle speed signal, checking
 
     
Notes:  
     
The vehicle speed signal is generated by the 
Vehicle Speed Sensor (VSS) -G68- (at 
transmission) and processed in the instrument 
cluster. 
     The processed signal enters at terminal 54 of 
the ECM and is used for idle stabilization and 
tip-in shock reduction during shifting. 
     
Test requirement:  
     Function and display of speedometer OK. 
Troubleshooting: 
     
       Electrical Wiring Diagrams, Troubleshooting & 
Component Locations binder   
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Page 6 of 44

24-170
      
-  Connect VAG1598/31 test box at wiring harness 
to ECM, do not connect ECM   Page 24
-17
 . 
     
-  Connect VAG1527B voltage tester to sockets 3 
(B+) and 54 (VSS) of VAG1598/31 test box. 
     
-  Switch ignition on and turn front left wheel by 
hand. 
     
 
LED must blink (very brief blink signal).
      If LED does not blink:  
     
-  Check the following wire connection for open 
circuit and short circuit to Ground (GND) and B+:
     
Test box  
VAG1598/31  
Socket  
Instrument cluster  
  
Terminal  
54    Electrical Wiring Diagrams, 
Troubleshooting & Component 
Locations binder   
     
-  Repair open circuit or short circuit if 
necessary. 
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Page 7 of 44

24-171
      
Wire for fuel level signal, checking
 
     
Notes:  
     
The Engine Control Module (ECM) receives the 
fuel level signal from the instrument cluster. 
     The processed signal enters at terminal 30 of 
the ECM and is used to determine the cause of 
certain recognized malfunctions (e.g. 
combustion misfires). 
     
-  Connect VAG1598/31 test box at wiring harness 
to ECM, do not connect ECM   Page 24
-17
 . 
     
-  Check the following wire connection for open 
circuit and short circuit to Ground (GND) and B+:
     
Test box  
VAG1598/31  
Socket  
Instrument cluster  
  
Terminal  
30    Electrical Wiring Diagrams, 
Troubleshooting & Component 
Locations binder   
     
-  Repair open circuit or short circuit if 
necessary. 
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Page 11 of 44

24-174
      
-  Depress gas pedal completely (swiftly) and then 
release it (brief acceleration). 
     
 
Specified value in display field 4: Indication 
jumps for a few seconds from "Compr. ON" 
to "Compr. OFF" (compressor is switched off 
when vehicle accelerates). 
      If indications do not resemble description:  
     
-  Connect VAG1598/31 test box at wiring harness 
to ECM, do not connect ECM   Page 24
-17
 . 
     
-  Check the following wire connection for open 
circuit and short circuit to Ground (GND) and B+:
     
Test box  
VAG1598/31  
Socket  
A/C control  
head -E87-  
Terminal  
41    Electrical Wiring Diagrams, 
Troubleshooting & Component 
Locations binder   
     
-  Repair open circuit or short circuit if 
necessary. 
     
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Page 12 of 44

-  If there are no malfunctions in the wiring, check 
function of A/C system. 
     
       Repair Manual, Heating & Air Conditioning, Repair Group 01
   
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Page 14 of 44

24-176
 If specified values are not obtained:  
Read Measuring Value Block 
Q
Input displa
y group number XXX
    
When indicated on display:  
-  Press buttons -0-, -5- and -6- to select "display group number 056" and press -Q-
button to confirm input. 
-  Switch on A/C system, press "Auto" button and select the lowest temperature.
-  Check indications in display field 3 and 4.
  
Display fields  
  
1   2   3   4  
Display group 056: Idle stabilization with engine at idle and operating temperature  
Display   xxx /min   xxx /min  
---  
---  
Indicated   Engine speed (actual)   Engine speed (specified)  
A/C readiness  
A/C compressor  
Functional range    
    
A/C - LOW  
A/C - HIGH  Compr. OFF  
Compr. ON  
Specified value  
720 to 820 RPM 
1)  
630 to 730 RPM 2)  760 RPM 
1)  
680 RPM 2)  A/C - HIGH  
Compr. ON  
1) Front Wheel Drive Vehicles  2) All-Wheel Drive Vehicles  
-  Connect VAG1598/31 test box at wiring harness to ECM, do not connect ECM   Page 24
-17
 .
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Page 15 of 44

24-177
      
-  Check the following wire connection for open 
circuit and short circuit to Ground (GND) and B+:
     
Test box  
VAG1598/31  
Socket  
A/C control  
head -E87-  
Terminal  
40    Electrical Wiring Diagrams, 
Troubleshooting & Component 
Locations binder   
     
-  Repair open circuit or short circuit if 
necessary. 
     
-  If there are no malfunctions in the wiring, check 
function of A/C system. 
     
       Repair Manual, Heating & Air Conditioning, 
Repair Group 01
   
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Page 22 of 44

24-182
       If LED does not light up:  
     
-  Check wire connection from terminal 1 or 3 of 
connector for open circuit and short circuit to 
Ground (GND): 
     
       Electrical Wiring Diagrams, Troubleshooting & 
Component Locations binder        
-  Repair open circuit or short circuit if 
necessary. 
      If LED lights up:  
     
Checking activation  
     
-  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 and short circuit to Ground (GND) and B+:
     
Harness connector  
Terminal  
VAG1598/31 test box  
Socket  
2   56  
4   55  
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