diagram AUDI A4 1996 B5 / 1.G AHA Engine Multiport Fuel Injection And Ignition System Owner's Manual

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
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24-98
If the LED test light does not light up:

- Repeat test at other terminal of fuse 34.

If the LED test light still does not light up:
- Check wiring for open circuit between fuse 34 and terminal 31 at relay
position 6, using the applicable wiring diagram. Repair wiring as
necessary.

Specified value: max. 1.5
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24-99

Checking fuel pump relay voltage supply and
actuation

- Remove fuel pump relay -J17- from relay panel
position 6.

Checking fuel pump relay voltage supply

- Switch ignition on.

If voltage is NOT OK: - Connect multimeter US1119 (Fluke 83 or similar) and check for voltage
at relay socket:

Terminals 28 (B+) and 34
Terminals 32 (B+) and 34
Specified values: approx. Battery Positive Voltage (B+)
- Repair wiring according to applicable wiring diagram.
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24-100

Checking fuel pump relay actuation

Note:
The LED light will light dimly before and after cranking the starter.
If the LED test light does not light up while cranking the starter, check
wiring as follows. - Connect VAG1527B LED voltage tester between relay socket terminals
28 (B+) and 29.
- Briefly crank starter.
LED test light must light up.

If resistance is NOT OK:
Electrical Wiring Diagrams, Troubleshooting & Component Locations
binder. - Connect VAG1598/22 test box to ECM harness connector page 01
-
67
. (Numbers marked on ECM connector match those on test box).
- Connect multimeter US1119 (Fluke 83 or equivalent) to check for open
circuit between relay socket terminal 29 and test box socket 4.

Specified value: max. 1 - Repair wiring using applicable wiring diagram.
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24-102

Fuel injectors, checking


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.
Activating fuel injectors via output Diagnostic
Test Mode (DTM) page 01-51


Required special tools and test equipment

VAG1598/22 test box
Multimeter US1119 (Fluke 83 or equivalent)
VAG1527B LED voltage tester
VW1594 connector test kit
Wiring diagram

Test requirements

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24-105

- Check wiring for open circuit between fuel
injector connector terminal 1 and relay panel,
according to wiring diagram.


Specified value: max. 15
- Check wiring for short circuits between wires
and connector terminals.


Specified value:
Fuel injector resistance, checking

If resistance is NOT OK: - Check resistance of individual fuel injectors.

Specified value: 13.5-15.5 - Replace affected fuel injector.
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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
.
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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
.
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yp
e=re
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