sensor AUDI TT 1996 8N / 1.G AEB ATW Engines Charge Air System With Turbocharger Workshop Manual
Page 25 of 42
21-66
 
  
Charge air pressure sensor -G31-, 
checking
 
Special tools and equipment  
 
VAG1526A
 VAG1594A
 VAG1598/31
 VAS5051 with VAG5051/1
- or 
 VAG1551 with VAG1551/3A
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Page 26 of 42
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Note:  
     The charge air pressure sensor -G31- and wire 
connections are monitored by the Engine Control 
Module (ECM). 
     
-  Connect VAS5051 tester or VAG1551 scan tool 
and select control module for engine electronics 
using "address word 01". Engine must run at idle 
for this: 
     
       Repair Manual, 1.8 Liter 4-Cyl. 5V Turbo Fuel 
Injection & Ignition, Repair Group 01        
-  Check DTC memory of Engine Control Module 
(ECM): 
     
       Repair Manual, 1.8 Liter 4-Cyl. 5V Turbo Fuel 
Injection & Ignition, Repair Group 01         If a malfunction relating to the charge air 
pressure sensor -G31- is indicated:  
     
Checking voltage supply  
     
-  Disconnect harness connector at charge air 
pressure sensor. 
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Page 29 of 42
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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.
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Page 30 of 42
If wire connection is OK:  
-  Replace charge air pressure sensor -G31-.
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Page 33 of 42
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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
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.GE02.21.3