AUDI A4 1997 B5 / 1.G Airbag Service OBD Workshop Manual

01-5


Airbag system (with and
without side airbag) On Board
Diagnostic (OBD)

General Information


Vehicles 1997
The airbag system includes a driver-side airbag,
passenger-side airbag, and two front seat belt
tensioners. These are ignited centrally by the
airbag control module -J234- if the specified
activation criteria are met during a crash.

Vehicles 1997 1999 : up to VIN 8D XA 200
000 The airbag system includes a driver-side airbag,
passenger-side airbag, two front seat belt
tensioners, side airbag, driver's side, side airbag,
passenger side, and two or three (1998 and on )
rear seat belt tensioners. If the specified
activation criteria are met during a crash, they
are ignited centrally by the airbag control module
-J234-.
Regardless of the type of crash or crash
intensity, the airbag control module sends a
"crash signal" to the central locking control
module. This function provides passive security.
With the help of the central locking system, it
unlocks the doors, opens the rear lid and blocks
Pa
ge 1 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

interior switches when an airbag is triggered.
Also, interior lighting is switched on. The "crash
signal" can be checked using the Output
Diagnostic Test Mode page 01
-44
.
Pa
ge 2 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

01-6

1999 vehicles : from VIN 8D XA 200 001 Airbag system includes: side airbag, passenger-
side airbag, two front seat belt tensioners, two
front side airbags, two or three rear seat belt
tensioners and side curtain airbags. In a crash
situation, these are ignited centrally by the airbag
control module -J234- when specified triggering
criteria are met.
In a crash situation, the control module sends a
crash signal to the central locking control
module. This function is a passive safety feature.
It releases door locks and the rear lid lock via the
central locking system if an airbag and/or belt
tensioner is triggered. Also, inside door lock
switches are blocked and interior lighting is
switched on. The "crash signal" can be checked
using output Diagnostic Test Mode (DTM)
page 01
-44
.
When the airbags and/or belt tensioners are
deployed, the control module will record the DTC
"Crash data stored."
Airbag control module -J234- must be replaced
following:

The 1st driver-side/passenger-side airbag
deployment.
The 3rd time front seat belt tensioners and/or
Pa
ge 3 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

side airbags are triggered.

For vehicles with airbag 8 ( 10/98) the crash
signal cannot be erased using the VAG1551
scan tool after the 3rd deployment.
Pa
ge 4 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

01-7

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

obtained by pressing the VAG1551 Scan Tool
(ST) HELP button.
The button is used to advance through the
program sequence.

- Switch printer on by pressing PRINT button
(indicator lamp in button lights up).

- Press button -1- to select "Rapid data transfer"
operating mode 1.
Pa
ge 8 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

01-9

Rapid data transfer
HELP
Insert address word XX

Indicated on display
Address word for the airbag system: 15
- Press buttons -1- and -5- to insert "Airbag" address word 15.
Rapid data transfer
Q
15 - Airba
g

Indicated on display
- Press -Q- button to confirm input.
Rapid data transfer Scan Tool sends address word 15

Indicated on display
Vehicles 1997:
8A0959655D
Airbag V AUDI
D02
Coding 00766
WSC 06812

Indicated on display after about 5 seconds
Vehicles 1997 up to 1999: VIN 8DXA 200 000
8D0959655C
Airbag 7
AUDI D00
Codin
g 00102
WSC 06812

Vehicles 1999 : from VIN 8D XA 200 001 - Indicated on display after approx. 5 seconds
8D0959655J
Airbag Front+Side
0004
Coding 01106
WSC 06812

- Indicated on display after approx. 5 seconds:
Front and side airbag or front and side curtain airbag
Pa
ge 9 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

01-10

All vehicles

-
Press button to advance through program
sequence. Rapid data transfer
HELP
Select function XX

Indicated on display
Note:
A list of available functions is printed out when the HELP button is
pressed.
On Board Diagnostic (OBD) functions
The following functions are possible:
01 - Check Control Module Versions page 01
-41

02 - Check DTC Memory page 01
-11

03 - Output Diagnostic Test Mode (vehicles 1997 1998 only page
01
-44
) (vehicles 1999 only page 01
-46
)
05 - Erase DTC Memory page 01
-137

06 - End Output page 01
-139

07 - Code Control Module page 01
-51

08 - Read Measuring Value Block page 01
-57

Note:
Pa
ge 10 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