light AUDI A4 2000 B5 / 1.G AHA Engine Multiport Fuel Injection And Ignition System User Guide

24-110

Checking for leaks

- Conduct output DTM, actuating cylinder 1
injector -N30- page 01
-51
(fuel pump must be
running).

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.

- Visually check injector for leaks.

With fuel pump running, only 1 to 2 drops can
drip in a minute (per injector).
If fuel loss is greater:

- Replace leaking injector
Installation of the injectors is in reverse order of
removal.

- Replace O-rings on all injectors and coat O-rings
lightly with clean engine oil.

Pa
ge 140 of 166 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
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yp
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24-121

Checking EVAP canister purge regulator
valve voltage supply

Test conditions

Fuse for EVAP canister purge regulator
valve OK

- Disconnect harness connector from EVAP
canister purge regulator valve.

If LED test light does not light:
If wiring is OK: - Connect VAG1527B LED voltage tester between connector terminal 1
(B+) and engine Ground.
- Operate starter motor.
Specified value: LED must light up
- Check wiring for open circuit between connector terminal 1 and fuse,
according to wiring diagram; repair if necessary.

Specified value: 1.0 max.- Check fuel pump relay page 24
-95
.
Pa
ge 158 of 166 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
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play?action=Goto&t
yp
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pair&id=AUDI.B5.FU03.24.1

24-122

Checking signal to EVAP canister purge
regulator valve

If LED test light does not blink, or stays on:
If LED test light does not blink: - Connect VAG1527B LED voltage tester between connector terminals 1
(B+) and 2.
- Start output Diagnostic Test Mode (DTM) for EVAP canister purge
regulator valve -N80- page 01
-51
.
LED must blink
- Connect VAG1598/22 test box to ECM harness connector page 01
-
67
.

If LED test light stays on: - Check wiring between connector terminal 2 and Motronic ECM terminal
15 for open circuit or short circuit to B+.
- Check wiring between connector terminal 2 and Motronic ECM terminal
15 for short circuit to Ground.
Pa
ge 159 of 166 Motronic Multi
port Fuel In
jection
(MFI
) and i
gnition s
ystem
11/23/2002 htt
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU03.24.1

24-125

Voltage supply, checking

If LED tester does not light: - Disconnect harness connector for LDP -V144-.
- Connect VAG1527B LED voltage tester between connector terminal 3
(B+) and engine Ground.
- Start engine and run engine at idle.
LED must light up.
- Check fuse for LDP -V144-.
- Check wiring for open circuit between terminal 3 and fuse, according to
wiring diagram.

Specified value: max. 0.5 .- Check fuel pump relay and signal to relay page 24
-95
.
Pa
ge 162 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