ignition AUDI A4 1999 B5 / 1.G Airbag Service OBD Workshop Manual

01-7

All vehicles
The control module detects malfunctions and
errors in the airbag system and stores them in
permanent memory.
After the ignition is switched on, the airbag
Malfunction Indicator Lamp (MIL) -K75- lights for
about 4 seconds and then goes out.

If the airbag Malfunction Indicator Lamp (MIL) -
K75- does not go out after approximately 4
seconds, the voltage supply for the airbag
control module -J234- is not OK. Check DTC
memory page 01
-11
.

If the airbag Malfunction Indicator Lamp (MIL) -
K75- goes out after 4 seconds and then lights
again, either the control module is not coded,
an incorrect control module has been installed
or a malfunction is present. Check DTC
memory page 01
-11
.

CAUTION!

Wiring must only be checked visually!
Do not perform an electrical continuity check
or circuit analysis!

Pa
ge 5 of 74 Airba
g system
(with and without side airba
g)
On Board Dia
gnostic
(OBD
)
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.BD04.01.2

Check wire routing only when ignition is
switched off!
Pa
ge 6 of 74 Airba
g system
(with and without side airba
g)
On Board Dia
gnostic
(OBD
)
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.BD04.01.2

01-8

Airbag system On Board Diagnostic
(OBD), initiating


Requirements

Power supply and fuses for relevant system
OK

Electrical Wiring Diagrams, Troubleshooting &
Component Locations binder

VAG1551 Scan Tool (ST) connected page 01
-1

Ignition switched on

Notes:
Malfunctions which have only occurred briefly
are classified as "Sporadic malfunctions" and
are identified by the "/SP" on the right side of
the display.
To eliminate these sporadic malfunctions, erase
DTC memory before starting repair work.
Additional operating instructions can be
Pa
ge 7 of 74 Airba
g system
(with and without side airba
g)
On Board Dia
gnostic
(OBD
)
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.BD04.01.2

01-20

DTC


VAG 1551 scan tool
display Possible cause
Corrective action
00594
Airbag Ignition
Circuit
Short circuit to B+
Wiring damaged
Airbag control module -
J234- faulty Electrical Wiring Diagrams, Troubleshooting & Component
Locations binder - Repair wiring according to wiring diagram.
- Replace airbag control module -J234-.
00594
Airbag Ignition
Circuit
Short circuit to
Ground
Wiring damaged
Spiral spring faulty
Driver-side airbag faulty
Airbag control module -
J234- faulty Electrical Wiring Diagrams, Troubleshooting & Component
Locations binder - Repair wiring according to wiring diagram.
- Check spiral spring.
- Replace driver-side airbag unit.
- Replace airbag control module -J234-.
00595
Crash Data Stored

Frontal collision
Side collision- Replace airbag control module, airbag units, seat belt tensioners
and if necessary, faulty components.
Pa
ge 23 of 74 Airba
g system
(with and without side airba
g)
On Board Dia
gnostic
(OBD
)
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.BD04.01.2

01-49

Output Diagnostic Test Mode Signal: Open central lockin
g system

Indicated on display
Engine must stop running
Central locking must switch to "open."
Emergency flashers and interior lights switch on.
Notes: - Operate interior switch. Central locking must not switch to "closed" as
long as DTC is still stored in central locking control module.
After this procedure step, DTC 01366 is stored in the DTC memory of
the central locking control module. After completion of output Diagnostic Test Mode (DTM), the DTC
memory of the central locking control module must be checked and
this DTC must be erased page 01
-74
.
Several DTCs will be stored in the DTC memory of the Engine Control
Module (ECM) after this procedure. After completing output Diagnostic Test Mode (DTM), the DTC
memory of the Engine Control Module (ECM) must be checked and
erased. This procedure varies depending on the fuel injection and
ignition system installed in the vehicle. Refer to Repair Group 01 of
the appropriate repair manual DTC memory, checking and erasing. Depending on engine type, fuel shut-off is a running-change as of KW
18.99.
Pa
ge 66 of 74 Airba
g system
(with and without side airba
g)
On Board Dia
gnostic
(OBD
)
11/20/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.BD04.01.2