1999 AUDI A4 engine

24-1


Motronic fuel injection
system, servicing

Safety precautions

If special testing equipment is required during
road test, note the following:

WARNING!

Test equipment must always be secured to
the rear seat and operated from there by a
second person.
If test and measuring equipment is operated
from the passenger seat, the person seated
there could be injured in the event of an
accident involving deployment of the
passenger-side airbag.
To reduce the risk of personal injury and/or
damage to the fuel injection and ignition system,
always observe the following:
Only disconnect and reconnect wires for
injection and ignition system, including test
leads, when ignition is turned off.
If engine is to be cranked at starting RPM
without starting (e.g. for compression testing),
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24-2

It is possible that the control module will
recognize a malfunction and store a DTC during
some tests. After completing all tests and
repairs, DTC memory should therefore be
checked and erased if necessary. Readiness
code must be generated after DTC memory is
erased Page 01
-73
.

Always switch ignition off before cleaning
engine.
The battery should only be disconnected and
reconnected when the ignition is turned off,
since otherwise the Engine Control Module
(ECM) can be damaged.

WARNING!

Fuel system is under pressure! Before
opening system, place rags around the
connection point. Then release pressure by
carefully loosening connection.
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24-4
Technical data

Engine identification

ATW (1.8 L / 5V/ 110 kW-engine)
Idle speed
Engine speed cannot be adjusted, it is regulated by idle
stabilization
Front Wheel Drive
(FWD)
All Wheel Drive (AWD)
740 to 860 RPM
800 to 920 RPM
Engine speed (RPM) limitation
via fuel injector shut-off
about 6800 RPM
Fuel pressure at idle speed Vacuum hose
connected about 3.5 bar positive pressure

Vacuum hose
disconnected about 4.0 bar positive pressure
Residual pressure after 10 min. at least 2.5 bar positive pressure
Fuel injectors Injection stream Dual-hole nozzle / same for all
injectors

Injection quantity (30 s)
135 10 ml

Resistance
(room temperature)
12 to 13
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24-6


Repair Manual, 1.8 Liter 4
-Cyl. 5V Turbo Engine
Mechanical, Engine Code(s): AEB, ATW, Repair Group 26; Secondary Air Injection (AIR) system, checking
3 -
Oxygen Sensor (O2S) behind Three Way
Catalytic Converter (TWC) -G130-, 55 Nm Check Oxygen Sensor (O2S) and oxygen
sensor control behind Three Way Catalytic
Converter (TWC) Page 24
-87

Check oxygen sensor heater for Oxygen
Sensor (O2S) behind Three Way Catalytic
Converter (TWC) Page 24
-99

Removing and installing Page 24
-105
4 -
Combination valve for secondary air
injection (AIR)
Checking, removing and installing:
5 -
Engine Coolant Temperature (ECT) sensor
-G62-
Checking Page 28
-30
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24-7


Repair Manual, 1.8 Liter 4
-Cyl. 5V Turbo Engine
Mechanical, Engine Code(s): AEB, ATW, Repair Group 26; Secondary Air Injection (AIR) system, checking
6 -
Fuel pressure regulator Checking Page 24
-33
7 -
Engine Speed (RPM) sensor -G28-
Checking Page 28
-26
8 -
Secondary Air Injection (AIR) solenoid
valve-N112-
Installation position Page 24
-14
, Fig.
4
Checking:Green harness connector
9 -
Bracket for harness connectors Component location Page 24
-13
, Fig.
1

Accessible with coolant expansion tank
unbolted and swung to the side.
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24-9


Repair Manual, 1.8 Liter 4
-Cyl. 5V Turbo Engine
Mechanical, Engine Code(s): AEB, ATW, Repair Group 26; Secondary Air Injection (AIR) system, checking
13 -
E-box, plenum chamber Installation locations Page 24
-15
, Fig.
6

Installation location for motronic Engine
Control Module (ECM) -J220- with
integrated Barometric pressure (BARO)
sensor -F96- Check voltage supply of Engine Control
Module (ECM) Page 28
-36

Procedure to follow after open circuit in
voltage supply Page 24
-22

Replacing Engine Control Module (ECM)
Page 24
-23

Installation location of Secondary Air
Injection (AIR) pump relay -J299- Check Secondary Air Injection (AIR) pump
relay -J299-:
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24-10


Repair Manual, 1.8 Liter 4
-Cyl. 5V Turbo Engine
Mechanical, Engine Code(s): AEB, ATW, Repair Group 21, Charge air system with turbocharger, checking

Installation location of motronic Engine Control
Module (ECM) power supply relay -J271-
Check motronic Engine Control Module (ECM)
power supply relay -J271- Page 28
-13

Installation location of fuse S130 for Secondary
Air Injection (AIR) pump
14 -
Clutch vacuum vent valve switch -F36-
Component location Page 24
-14
, Fig.
3

15 -
Charge air pressure sensor -G31-
Installation position Page 24
-16
, Fig.
7
Checking:
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24-12


Repair Manual, 1.8 Liter 4
-Cyl. 5V Turbo Engine
Mechanical, Engine Code(s): AEB, ATW, Repair Group 21, Charge air system with turbocharger, checking

Repair Manual, 1.8 Liter 4
-Cyl. 5V Turbo Engine
Mechanical, Engine Code(s): AEB, ATW, Repair Group 26; Secondary Air Injection (AIR) system, checking
22 -
Fuel injectors -N30- through -N33- Checking Page 24
-38
Removing and installing Page 24
-46
23 -
Ignition coils -N-, -N128-, -N158-, -N163-
Checking Page 28
-4
24 -
Wastegate bypass regulator valve -N75-
Checking:
25 -
Mass Air Flow (MAF) sensor -G70-
Checking Page 24
-60
26 -
Secondary Air Injection (AIR) pump
motor-V101-
Checking:
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pair&id=AUDI.B5.FU06.24.1