Page 9 of 90
24-7
 
  
1 - 
Harness connector forOxygen Sensor 
(O2S) Behind Three Way Catalytic 
Converter (TWC) -G130 and Heater for 
Lambda-probe 1 -Z29 
4-pin green
2 - 
Harness connector forOxygen Sensor 
(O2S) 2 Behind Three Way Catalytic 
Converter (TWC) -G131 and Heater for 
Lambda-probe 2 -Z30 4-pin brown
3 - 
Harness connector for Heated Oxygen 
Sensor (HO2S) and Oxygen Sensor (O2S) 
Heater 4-pin black
4 - 
3-pin harness connector For Knock sensor (KS) 1 -G61
5 - 
Engine Coolant Temperature (ECT) 
Sensor -G62 On cooling pipe behind cylinder bank 1
6 - 
Wastegate Bypass Regulator Valve -N75 
7 - 
EVAP Canister Purge Regulator Valve -
N80 
Pa
ge 9 of 90 Motronic Multi
port Fuel In
jection 
(MFI
) system, servicin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.1 
     
        
        Page 31 of 90
24-27
      
Idle speed, checking
 
     
Test conditions  
     
No leaks in exhaust system 
     Coolant temperature at least 80 C 
     
Electrical consumers switched off (radiator 
fan must not run during the check) 
     A/C switched off 
     Pressure gauge not connected 
     Selector lever in position P or N (vehicles 
with automatic transmission) 
     
Checking idle speed  
     
Notes:  
     The idle speed cannot be adjusted.
     The idle speed is tested during the basic setting 
of the engine. 
Pa
ge 31 of 90 Motronic Multi
port Fuel In
jection 
(MFI
) system, servicin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.1 
     
        
        Page 69 of 90
24-59
      
Mass Air FLow (MAF) sensor -G70, 
checking
 
     
Requirements  
     
Coolant temperature at least 80 C (175 F) 
     
Electrical consumers switched off (radiator 
fan must not run during test) 
     A/C switched off 
     Fuse for mass air flow sensor OK 
     
       Electrical Wiring Diagrams, Troubleshooting & 
Component Locations   
     
Checking function  
     
-  Connect vehicle diagnostic, testing and 
information system VAS5051 or VAG1551 scan 
tool and select engine electronics control 
module by entering address word "01"   Page 
01
-9 . When doing this the engine must be at 
idle. 
Pa
ge 69 of 90 Motronic Multi
port Fuel In
jection 
(MFI
) system, servicin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.1