Page 14 of 81
24-13
 
    
The following harness connectors are located below the coolant 
expansion tank:  Fig. 1  Installation location, harness connectors
1 - 4-pin harness connector, brown
  for Oxygen Sensor (O2S) behind Three Way Catalytic Converter 
(TWC) -G130- and Oxygen Sensor (O2S) Heater 1 -Z29- (bank 1 
sensor 2) 
2 - 6-pin harness connector, black
  for Heated Oxygen Sensor (HO2S) -G39- before catalytic converter 
and Oxygen Sensor (O2S) Heater -Z19- (bank 1 sensor 1) 
3 - 3-pin harness connector, gray
  for Engine Speed (RPM) sensor -G28-
4 - 3-pin harness connector, blue
  for Knock Sensor (KS) 2 -G66-
5 - 3-pin harness connector, green
  for Knock Sensor (KS) 1 -G61-
    
Fuel Pump (FP) Relay -J17- is located at position 4 of central electrics in 
driver's footwell, left.  Fig. 2  Component locations Fuel Pump (FP) Relay -J17-
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        Page 16 of 81
24-15
 
    
Fig. 5  Installation position, Throttle Position (TP) sensor -G79- 
and sender 2 for accelerator pedal position -G185- 
    
Fig. 6  Installation positions in E-box, plenum chamber
1 - Engine Control Module (ECM)
2 - Secondary Air Injection (AIR) pump relay -J299-
3 - Motronic Engine Control Module (ECM) power supply relay -J271-
4 - Installation location of fuse S130 for Secondary Air Injection (AIR) 
pump 
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        Page 17 of 81
24-16
 
    
Charge air pressure sensor -G31- (arrow) bolted into charge air cooler at 
top  Fig. 7  Installation location, charge air pressure sensor -G31-
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        Page 18 of 81
24-17
 
  
Air cleaner, disassembling and 
assembling
 
1 - 
Lower part of air cleaner housing 
2 - 
Sleeve 
3 - 
Rubber grommet 
4 - 
Air duct 
to metering unit
5 - 
Seal 
6 - 
Mass Air Flow (MAF) sensor -G70- Checking  Page 24
-60
7 - 
Air duct 
8 - 
6 Nm 
9 - 
Upper part of air cleaner housing 
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        Page 50 of 81
24-45
 
  
 Repair Manual, 1.8 Liter 4
-Cyl. 5V Turbo Engine 
Mechanical, Engine Code(s): AEB, ATW, Repair Group 15; Cylinder head, removing and installing; Intake manifold, removing and installing
    11 - 
O-ring 
Always replace
12 - 
O-ring Always replace
13 - 
Retaining clip For fuel pressure regulator
14 - 
Retaining clip Make sure clip is correctly seated on fuel 
injector and fuel rail 
15 - 
Intake manifold With throttle valve control module -J338-With Intake Air Temperature (IAT) sensor -
G42- Removing
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        Page 51 of 81
24-46
      
Fuel injectors, removing and installing
 
    
-  Remove engine cover (arrows).
-  Disconnect wiring/connectors at:
- Fuel injectors -N30-, -N31-, -N32-, -N33-
- Intake Air Temperature (IAT) sensor -G42-
- Camshaft Position (CMP) sensor 2 -G40-
- Throttle valve control module -J338-
    
-  Remove retaining bolts for fuel supply rail and disconnect vacuum line 
at fuel pressure regulator (arrows). 
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        Page 69 of 81
24-60
 
  
Mass Air Flow (MAF) sensor -G70-, 
checking
 
Special tools and equipment  
 
VAG1526A
 VAG1594A
 VAG1598/31
 VAS5051 with VAG5051/1
- or 
 VAG1551 with VAG1551/3A
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        Page 73 of 81

24-63
 Evaluation display group 002  Display field: 
3  
Possible cause  
Corrective action  
less than 1.0 
ms   
Smaller values are only possible when driving in 
deceleration mode   
larger than 4.0 
ms   Engine under load due to power accessories.- Reduce load (A/C system/power 
steering/generator) 
  
 Poor idle (does not run on all cylinders)- Check spark plugs.
- Check fuel injectors   Page 24
-38
 .
  
 
Throttle valve control module - J338- faulty- Check throttle valve control module   
Page 24
-120
 
Display field: 
4  
Possible cause  
Corrective action  
smaller than 
2.0 g/s   
large false air mass between intake manifold and Mass Air 
Flow (MAF) sensor 
 Voltage supply of Mass Air Flow (MAF) sensor or wire 
connections to Engine Control Module (ECM) - Check intake system for leaks (false 
air)  Page 24
-68
 . 
- Check voltage supply and wire 
connections  Page 24
-64
 
larger than 4.5 
g/s   
Engine under load due to power accessories.- Reduce load (A/C system/power 
steering/generator) 
  
 Voltage supply of Mass Air Flow (MAF) sensor or wire 
connections to Engine Control Module (ECM) - Check voltage supply and wire 
connections  Page 24
-64
 
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