fuel AUDI A8 1999 D2 / 1.G AEB Engine Motronic MFI And Ignition System

24-1


Motronic Multiport Fuel
Injection (MFI) and ignition
system Component locations, overview

----
Data Link Connector (DLC)
Located under knee bar, left side of
steering wheel
----
Fuel pump relayPosition 6 on relay panel in driver's side
footwell
----
Oxygen Sensor (O2S) behind Three Way
Catalytic Converter (TWC) -G130- with
Oxygen Sensor (O2S) heater -Z29- In exhaust system behind TWC
----
EVAP system Leak Detection Pump (LDP)
-V144- In left-rear wheelhousing behind splash
shield
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24-2


1 -
Heated Oxygen Sensor (HO2S) -G39- with
Oxygen Sensor (O2S) heater -Z19-
2 -
Engine Coolant Temperature (ECT) sensor
-G62-
4-pin connector
3 -
Harness connector for: Heated Oxygen Sensor (HO2S) -G39- and
Oxygen Sensor (O2S) heater -Z19- (4-pin,
brown) Oxygen Sensor (O2S) behind Three Way
Catalytic Converter (TWC) -G130- with
Oxygen Sensor (O2S) heater -Z29- (4-pin,
black) Engine speed (RPM) sensor -G28- (3-pin,
gray) Knock sensor (KS) 1 -G61 (3-pin, green)Knock sensor (KS) 2 -G66- (3-pin, blue)
4 -
Electronics box (E-box) with: Motronic Engine Control Module (ECM) -
J220- Barometric Pressure (BARO) sensor -F96-
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24-3


5 -
EVAP canister purge regulator valve -N80-
6 -
Power output stage -N122-
5-pin connector: signal wiring from ECM4-pin connector: coil primary circuit
connections
7 -
Mass Air Flow (MAF) sensor -G70- In upper air cleaner housing
8 -
Wastegate bypass regulator valve -N75-
9 -
Ignition coils Cylinder 1: -N-Cylinder 2: -N128-Cylinder 3: -N158-Cylinder 4: -N163-
10 -
Fuel injectors Cylinder 1: -N30-Cylinder 2: -N31-Cylinder 3: -N32-Cylinder 4: -N33-
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24-4


11 -
Camshaft Position (CMP) sensor -G40-
12 -
Knock Sensor (KS) 1 -G61-
13 -
Knock Sensor (KS) 2 -G66-
14 -
Engine speed (RPM) sensor -G28-
(behind oil filter housing on engine cylinder
block)
15 -
Intake Air Temperature (IAT) sensor -G42-
16 -
Throttle valve control module -J338-
Including:
Throttle drive -G186-Angle sensor 1 for throttle drive -G187-Throttle Position (TP) sensor -G69-Closed Throttle Position (CTP) switch -
F60-
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24-5

Safety precautions


WARNING!

Fire hazard! Do not smoke, work near heaters
or open flame, or have anything nearby that
could ignite fuel. The fuel system is under
pressure. Before opening, cover connections
with a rag, and open carefully to release
pressure. Be alert when working on or near
the engine and ignition wires. High secondary
ignition voltage can cause serious personal
injury and damage vehicle components.

DO NOT touch or disconnect ignition system
wires when the engine is running or being
cranked at starting RPM.
DO NOT operate starter if fuel injectors are
removed.

Be sure the ignition is switched OFF, when:
Disconnecting or connecting the battery,
ignition wires, or test equipment leads
Disconnecting fuel injection system wiring
Washing the engine or engine
compartment.
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BEFORE cranking engine at starting RPM
(e.g. for compression testing) disable ignition
and fuel injection systems:

Disconnect both ignition coil power output
stages, and both Motronic fuses at the E-box
in the plenum.
Disconnect harness connectors from all fuel
injectors.
Afterward, erase DTC memory.
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24-6

CAUTION!

BEFORE disconnecting the battery:

Stop the engine.
Be sure the ignition is switched OFF (also
applies when connecting the battery). Failure
to do so may damage the Engine Control
Module (ECM).
Be sure of the proper radio code (for vehicles
equipped with coded anti-theft radio).

Be sure the battery negative (-) cable is
disconnected, when:
Working on the electrical system
Resistance (spot) welding or electric arc
welding anywhere on the vehicle.

When connecting and disconnecting
electrical test equipment (LED voltage tester,
multimeter, etc.):
Be sure the ignition is switched OFF.
Use correct adapters from the VW 1594
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connector test kit.

For any work affecting the Engine Control
Module (ECM):
BEFORE disconnecting the ECM harness
connector, switch the ignition OFF and WAIT
at least 20 seconds. Failure to do so may
damage the ECM.
DO NOT connect any outside voltage source
to stimulate an output signal at the ECM.
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24-7

Rules of cleanliness


CAUTION!

Whenever carrying out work on the fuel
supply and fuel injection systems, carefully
observe the following five rules of
cleanliness.
1. Thoroughly clean fuel system line and hose
connections and the surrounding area before
disconnecting.
2. Place removed components on a clean
surface and cover. Use plastic sheeting or paper.
Do not use fluffy rags that could leave lint!
3. Carefully cover over or seal any components
that have been opened if repairs are not carried
out immediately.
4. Install only clean parts:

Do not remove replacement parts from the
packaging until immediately before they are to
be installed.
Do not use parts that have been stored without
packaging (e.g. in toolboxes, etc.).
5. When the fuel system is opened:
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Avoid working with compressed air whenever
possible.
Avoid moving the vehicle if possible.
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11/19/2002 htt
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yp
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pair&id=AUDI.B5.FU02.24.1