1995 AUDI A4 sensor

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- beforecatalytic 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 electronics
in driver's footwell, left. Fig. 2 Component locations Fuel Pump (FP) Relay -J17-
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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) voltage supply relay -J271-
4 - Installation location of fuse S130 for Secondary Air Injection (AIR)
pump
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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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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
-59
7 -
Air duct
8 -
6 Nm
9 -
Upper part of air cleaner housing
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24-44


Repair Manual, 1.8 Liter 4
-Cyl. 5V Engine
Mechanical, Engine Code(s): AWM, 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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24-45

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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24-59


Mass Air Flow (MAF) sensor -G70-,
checking

Special Tools and Equipment

VAG1526A
VAG1594A
VAG1598/31
VAS5051 with VAG5051/1
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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
-37
.


Throttle valve control module - J338- faulty- Check throttle valve control module
Page 24
-124

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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