AUDI A4 1999 B5 / 1.G ATW Engine Motronic Fuel Injection Syst

Page 01
-49
and activate Evaporative Emission
(EVAP) canister purge regulator valve -N80-.
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A - If relay does not trigger:
B - If relay triggers, but Fuel Pump (FP) does not run:
Check voltage supply of Fuel Pump (FP) relay
Fuel Pump (FP) relay (at position 4 of central electrics in driver's
footwell, left) must trigger and Fuel Pump (FP) must run.
- Check voltage supply of Fuel Pump (FP) relay Page 24
-55
.
- Checking activation of Fuel Pump (FP) relay Page 24
-56
.
- Check voltage supply for Fuel Pump (FP) and components (via Fuel
Pump -FP- relay) Page 24
-58
.
- Remove Fuel Pump (FP) relay.

- Connect multimeter to terminal 17 of relay socket and Ground (GND)
for voltage measurement.

Specification: approx. battery voltage
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If specified value is not obtained:

- Replace central electrics.

Checking activation of Fuel Pump (FP) relay

- Switch ignition off.

- Connect VAG1598/31 test box at wiring harness
to Engine Control Module (ECM), do not connect
ECM Page 24
-19
.

- Switch ignition on.

- Bridge terminals 1 and 65 at test box using wires
from VAG1594A adapter test kit.

If relay triggers now, but didn't during output DTM:
If relay does not trigger:
Fuel Pump (FP) relay (at position 4 of central electrics in driver's
footwell, left) must trigger.
- Replace Engine Control Module (ECM) Page 24
-23
- Switch ignition off.
- Remove cable bridge.
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- Remove Fuel Pump (FP) relay.
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If specified value is not obtained:
Electrical Wiring Diagrams, Troubleshooting & Component Locations
If specified value is obtained: - Connect multimeter for voltage measurement as follows.Central electronics in driver-side footwell, left,
position 4
Terminal
Measure to
19 Engine Ground
(GND)
- Switch ignition on.

Specification: approx. battery voltage
- Check wire connections.
- Check following wire connection for open circuit and short circuit to
Ground (GND) and B+: Central electronics in driver-side footwell, left,
position 4
Terminal
VAG1598/31 test
box


Socket
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16 65
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- Repair open circuit or short circuit if
necessary.
If no malfunctions are detected:

- Replace Fuel Pump (FP) relay -J17-.

- Re-connect Engine Control Module (ECM).

Check voltage supply for Fuel Pump (FP) and
components

- Remove fuses S228, S232, and S234 (positions 28, 32, and 34) from
fuse holder.
- Initiate output Diagnostic Test Mode (DTM) Page 01
-49
and activate
Evaporative Emission (EVAP) canister purge regulator valve -N80-.
- Connect multimeter for voltage measurement to Ground (GND) and to
one terminal of following fuses in fuse holder. Circlip
Specified value at one of the terminals
S228 approx. battery voltage
S232 approx. battery voltage
S234 approx. battery voltage
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If specified values are not obtained:

- Repeat test at another terminal of fuse socket.
If specified values are not obtained again:

- Check wire connections.

Electrical Wiring Diagrams, Troubleshooting &
Component Locations If no malfunctions are detected:

- Replace Fuel Pump (FP) relay -J17-.

- Re-insert fuses.
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Mass Air Flow (MAF) sensor -G70-,
checking

Special tools and equipment

VAG1526A
VAG1594A
VAG1598/31
VAS5051 with VAG5051/1
- or
VAG1551 with VAG1551/3A
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Component location Overview of component
locations Page 24
-5

Test requirements:

Coolant Temperature at least 80 C.

Electrical consumers switched off (radiator
fan must NOT run during test).
A/C switched off.

Checking function

- Connect VAS5051 tester or VAG1551 scan tool
and select control module for engine electronics
using "address word" 01 Page 01
-10
. Engine
must run at idle.
Rapid data transfer
HELP
Select function XX

When indicated on display
- Press buttons -0- and -4- to select "Initiate basic setting" and press -Q-
button to confirm input.
Basic Setting
Q
Enter displa
y group number XXX

When indicated on display
- Press buttons -0-, -0- and -2- to select "display group number 002" and
press -Q- button to confirm input. When indicated on display
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pair&id=AUDI.B5.FU06.24.1