fuel pump AUDI A6 1999 C5 / 2.G AHA Engine Multiport Fuel Injection And Ignition System Workshop Manual

24-1


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

Data Link Connector (DLC)
Fuel pump relay
Oxygen Sensor (O2S) behind Three Way
Catalytic Converter (TWC) -G130-, with Oxygen
Sensor (O2S) heater -Z29-
Located under knee bar, left side of steering
wheel
Position 6 on relay panel in driver's side footwell
Bank 1, sensor 2
In exhaust system behind TWC
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24-2


Oxygen Sensor (O2S) 2 behind Three Way
Catalytic Converter (TWC) -G131-, with Oxygen
Sensor (O2S) heater -Z30-
EVAP system Leak Detection Pump (LDP) -
V144-
Bank 2, sensor 2
In exhaust system behind TWC
In left-rear wheelhousing behind splash shield
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24-4


6 -
Intake Air Temperature (IAT) sensor -G42-
7 -
Harness connector
For HO2S 2 -G108- with O2S heater -Z28-4-pin connector, blackFor bank 2, sensor 1
8 -
Harness connector For Knock Sensor (KS) 2 -G66-3-pin connector, blue
9 -
Harness connector For engine speed (RPM) sensor -G28-3-pin connector, gray
10 -
Electronics box (E-box)
Contains:Motronic Engine Control Module (ECM) -
J220- Secondary Air Injection (AIR) pump relay -
J299-
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24-8


26 -
Knock Sensor (KS) 1 -G61-
27 -
Fuel injectors
Cylinder 1: -N30-Cylinder 2: -N31-Cylinder 3: -N32-Cylinder 4: -N33-Cylinder 5: -N83-Cylinder 6: -N84-
28 -
Valve 1 for camshaft adjustment -N205-
29 -
Secondary Air Injection (AIR) pump motor
-V101-
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output stage, and fuse for fuel pump.
Disconnect harness connectors from all fuel
injectors.
Afterward, erase Diagnostic Trouble Code
(DTC) memory.
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24-95

Fuel pump relay and connections,
checking


The fuel pump relay is located at relay position 6 on the relay panel on the
left side under the instrument panel.
Checking function of fuel pump relay -J17-
- Remove storage shelf in left-front footwell.

- Remove fuses 28, 29 and 34 from fuse panel.
- Connect VAG1527B LED voltage tester between Ground and one of
the two terminals for fuse 28.
- Briefly crank starter.

LED test light must light up.
Fuel pump relay must be actuated (can be felt and heard)
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24-96
If the fuel pump does not respond:

- Check fuel pump relay actuation page 24
-
99
.
If the LED test light does not light up:

- Repeat test at other terminal of fuse 28.

If the LED light still does not light up:
- Check wiring for open or short circuits between fuse 28 and terminal 30
at relay position 6, using the applicable wiring diagram. Repair wiring
as necessary.

Specified value: max. 1.5

Note:
This step lets the fuel pump run without the engine running. The closed
throttle position switch must be closed during the test, or the selected fuel
injector will discharge fuel when it is actuated 5 times. - Connect VAG1527B LED voltage tester between Ground and one of
the two terminals for fuse 29.
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port Fuel In
jection
(MFI
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- Initiate output Diagnostic Test Mode (DTM) and advance to test of
cylinder 1 fuel injector -N30- page 01
-51
.

LED test light must light up
Fuel pump relay must be activated
Fuel pump must run
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24-97
If the LED test light does not light up:

- Repeat test at other terminal of fuse 29.

If the LED test light still does not light up:
- Check wiring for open circuit between fuse 29 and terminal 30 at relay
position 6, using the applicable wiring diagram. Repair wiring as
necessary.

Specified value: max. 1.5

Note:
This step lets the fuel pump run without the engine running. The closed
throttle position switch must be closed during the test, or the selected fuel
injector will discharge fuel when it is actuated 5 times. - Connect VAG1527 LED voltage tester between Ground and one of the
two terminals of fuse 34.
- Initiate output Diagnostic Test Mode (DTM) and advance to test of
cylinder 1 fuel injector -N30- page 01
-51
.

LED test light must light up
Fuel pump relay must be activated
Pa
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port Fuel In
jection
(MFI
) and i
gnition s
ystem
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Fuel pump must run
Pa
ge 125 of 166 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/23/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.24.1