21-68
      
-  Switch ignition on.
     
 
Specified value: approx. 5 V
      If specified value is not obtained:  
    
 Repair Manual, 1.8 Liter 4-Cyl. 5V Turbo Fuel Injection & Ignition, 
Repair Group 24    -  Connect VAG1598/31 test box to wiring harness -2- for Engine Control 
Module (ECM), also connect ECM -1-. Connect Ground (GND) clamp -
3- to negative battery post. 
    
If the specified value is met:  -  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   108  
3   98  
-  Repair open circuit or short circuit if necessary.
Pa
ge 28 of 42 Char
ge air s
ystem with turbochar
ger 
(en
gine code ATW
)
11/18/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE02.21.3 
21-69
      
Checking signal wire  
     
-  Connect harness connector at charge air 
pressure sensor. 
     
-  Connect multimeter to socket 101 and socket 
108 of test box for voltage measurement. 
     
-  Start engine and run at idle.
     
 
Specified value: approx. 1.90 V
     
-  Bring up engine RPM by suddenly depressing 
pedal. 
     
 Specified value: 2.00-3.00 V
      If specified values are not obtained:  
    
-  Check the following wire connection for open circuit and short circuit to 
Ground (GND) and B+: Harness connector  
terminal  
VAG1598/31 test box  
socket  
4   101  
-  Repair open circuit or short circuit if necessary.
Pa
ge 29 of 42 Char
ge air s
ystem with turbochar
ger 
(en
gine code ATW
)
11/18/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE02.21.3