Page 12 of 42
21-55
      
Test requirements  
     
All hoses and wires have been checked for 
proper seating and seal. 
     DTC memory checked 
     
       Repair Manual, 1.8 Liter 4-Cyl. 5V Turbo Fuel 
Injection & Ignition, Repair Group 01   
     
Output Diagnostic Test Mode (DTM) 
performed 
     
       Repair Manual, 1.8 Liter 4-Cyl. 5V Turbo Fuel 
Injection & Ignition, Repair Group 01   
     
Vehicle tester VAS 5051 or VAG 1551 
connected. 
     
Test sequence  
     
WARNING! 
     
To reduce the risk of accident or injury while 
carrying out tests and measurements during 
a road test, observe safety precautions   
Page 21
-40
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Pa
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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
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pair&id=AUDI.B5.GE02.21.3 
     
        
        Page 32 of 42
The shop air supply line will later be attached to the inlet of VAG 1687.  -  Close valve -3- before gauge.
-  Close valve -4- after gauge.
-  Remove female fitting from tester (arrow) and install an appropriate 
"male" air fitting that will connect to your shop air supply line (
WARNING!). 
Pa
ge 32 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 
     
        
        Page 33 of 42

21-71
      
WARNING! 
     
Use only approved air fittings to adapt shop 
air supply line to VAG 1687 tester. 
     
Special tool VAG 1687/1 pressure adapter, 
installing (1.8L Turbo)  
     
-  Separate intake hose from Mass Air Flow (MAF) 
sensor assembly. 
    
Special tool VAG 1687/1 pressure adapter, installing (2.7L BiTurbo)  
 Repair Manual, Maintenance; Air cleaner housing, cleaning; Air cleaner element, replacing
    -  Insert VAG 1687/1 pressure adapter in intake hose -black arrow- using 
existing clamp (as shown). 
-  Remove crankcase ventilation tube from intake hose at -white arrow-.
-  Remove upper air cleaner housing and hoses to intake manifold as 
necessary 
    
-  Insert VAG 1687/1 pressure adapter in intake hose -white arrow- using 
existing clamp (as shown). 
-  Disconnect engine crankcase ventilation hose from intake manifold -
black arrow-. 
- 
Plug intake manifold fitting (for crankcase ventilation hose) with 
appropriate hose and metal plug using clamps supplied with VAG 
Pa
ge 33 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