fuel AUDI A4 1999 B5 / 1.G APB Engine Additional Signals Checking Workshop Manual

24-180

Fuel consumption signal for on-board
computer, checking


Notes:

The fuel consumption signal is calculated by the
engine control module (on the basis of the
injection period) and passed on to the on-board
computer. The fuel consumption signal is taken
from terminal 81 on the Engine Control Module
(ECM).
Checking fuel consumption signal

Electrical Wiring Diagrams, Troubleshooting &
Component Locations
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24-184

Fuel tank level signal, checking


Note:

The Engine Control Module (ECM) receives the
fuel tank level signal from the instrument
cluster.
The processed signal enters on terminal 30 the
Engine Control Module (ECM) and is used to
determine certain malfunctions (e.g.: misfire)

- Connect VAG1598/31 test box to wiring harness
for engine control module. Do not connect to the
engine control module itself Page 24
-20
.

- Check wiring from test box socket 30 to
instrument cluster according to wiring diagram
for an open circuit and short circuit to B+/Ground
(GND).
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24-196

Crash signal, checking

The Engine Control Module (ECM) receives the
crash signal ("Crash shut-down activated") from
the airbag control module.
If the airbag control module sends the crash
signal to the ECM (if an accident occurred or if a
output Diagnostic Test Mode (DTM) was carried
out), the ECM shuts off the fuel pump, that
means the engine stalls, however, afterwards the
engine can be started again (e.g. when removing
the vehicle from the accident area)
The ECM cannot switch off the fuel pump during
an accident if the malfunction "Crash Signal from
Airbag Control Unit/Range Performance" from
the airbag control module is sent to ECM. The
engine control module cannot recognize the
crash signal from the airbag control module; e.g.:
if the wiring between the ECM and the airbag
control module is faulty.

- Connect VAG1598/31 test box to wiring harness
for engine control module. Do not connect to the
engine control module itself Page 24
-20
.
Pa
ge 22 of 37 Additional si
gnals, checkin
g
11/22/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.FU04.24.6