wiring AUDI A8 1998 D2 / 1.G ATQ Engine Motronic Injection System Servicing User Guide
Page 73 of 78
24-61
      
Voltage supply for Mass Air Flow (MAF) 
sensor, checking  
     
-  Disconnect connector from Mass Air Flow (MAF) 
sensor. 
    
Note:  
Voltage is supplied to Mass Air Flow (MAF) sensor from Fuel Pump (FP) 
relay. 
If specified value is not obtained:  
 Electrical Wiring Diagrams, Troubleshooting & Component Locations 
binder    -  Connect multimeter for voltage measurement as follows.Harness connector  
Terminal  
Measure to  
3   Engine Ground (GND)  
-  Operate starter briefly. 
 
Specification: approx. battery voltage
-  Check wire connection from terminal 3 of connector to Fuel Pump (FP) 
relay via fuse for open circuit and short circuit to Ground (GND): 
Pa
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jection s
ystem, servicin
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11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
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e=re
pair&id=AUDI.B5.FU05.24.1 
Page 75 of 78
24-63
      
Check wire connections for Mass Air Flow 
(MAF) sensor  
     
Note:  
     Signal wire is also checked during wire test. 
     
-  Connect VAG1598/31 test box at wiring harness 
to ECM, do not connect ECM   Page 24
-17
 . 
    
If wire connection is OK:  -  Check the following wire connections for open circuit and short circuit 
to Ground (GND) and B+: Harness connector  
Terminal  
VAG1598/31 test box  
Socket  
1   53  
2   27  
4   29  
-  Repair open circuit or short circuit if necessary.
-  Also check all wires for short circuit to each other.
-  Replace Mass Air Flow (MAF) sensor -G70-.
Pa
ge 75 of 78 Motronic in
jection s
ystem, servicin
g
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU05.24.1