instrument cluster AUDI A6 1997 C5 / 2.G AHA Engine Auxiliary Signals Checking Workshop Manual
Page 9 of 22
     
Read safety precautions for test driving vehicles 
while using test equipment   page 24
-9 . 
     
The speed signal is generated by the vehicle 
speed sensor (at the transmission), and 
processed at the speedometer/odometer in the 
instrument cluster. 
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Page 13 of 22
24-171
      
Continuation  
      If no speed was indicated:  
    
Notes: 
If the LED does not blink:  
If the wiring is OK and the LED does not blink:  
 Repair Manual, Electrical Equipment, Repair Group 90
    -  Connect VAG1598/22 test box to ECM harness connector   page 01
-
67
 . 
-  Connect VAG1527B LED voltage tester between ECM/test box sockets 
3 (B+) and 20 (signal). 
-  Lift vehicle at left-front until wheel is free.
-  Switch ignition on and rotate left-front wheel by hand.
   LED must blink (very brief blink)
The right-front wheel must not rotate; block it if necessary.For LEDs with little voltage consumption, the LED lights up at half 
strength when the ignition is switched on. 
-  Check wiring from ECM connector, terminal 20 to instrument cluster for 
open circuit or short circuit   Electrical Wiring Diagrams, 
Troubleshooting & Component Locations binder. 
- 
Check readiness code   page 01
-70
 . If Diagnostic Trouble Code 
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Page 22 of 22
24-177
      
-  Conduct a test drive (  Safety precautions   
page 24
-9 ). 
     
-  Check DTC memory of ECM   page 01
-16
 .
      If only the DTC "Fuel level too low" (SAE P1250 / 
VAG 17658) is stored in the DTC memory.  
    
 Electrical Wiring Diagrams, Troubleshooting & Component Locations 
binder    -  Connect VAG1598/22 test box to ECM harness connector   page 01
-
67
 . 
-  Check wire from terminal 21 of test box to instrument cluster for open 
circuit or short circuit per wiring diagram. 
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