Page 2 of 88
Downloaded from www.Manualslib.com manuals search engine
2
Advance by technology
The new Audi A4,
a vehicle which combines driving pleasure and good sense
with the highest level of quality and sports styling.
Control unit for vehicle electrical system
...48
New engine programme
...18
Electronic stability programme with
brake assistance
...32
Steering column switch module
...44
Crash sensors for front airbag
...14
Multi-communication bar
...72
Trapezium link
rear axle
...27
Aero-floor
...7
Page 5 of 88

Downloaded from www.Manualslib.com manuals search engine
5
High safety standards
With a thoroughly optimised body design and
comprehensive safety equipment, the new
Audi A4 is able to comply with all current valid
safety standards, throughout the world.
Crash sensors for the front airbags integrated
directly into the bumper bar, improve occu-
pant protection.
Finely-tuned aerodynamics
Despite the greater frontal area and the cool-
ing air current for the air conditioner (stand-
ard), it was possible to improve the C
D
value
by 5 %, in comparison to its predecessor,
to 0.28.
A special feature is the so-called aero-floor,
which provides for optimal airflow on the
underside of the vehicle.
Communication centre on wheels
With regard to infotainment, the new
Audi A4 leaves nothing to be desired.
4 different audio systems, 2 differently config-
ured Navigation systems and a car phone
with voice operation are on offer.
Electronic stability programme (ESP)
including brake assistant
For the latest ESP generation, the hydraulic
brake assistant is an integral part of the
standard equipment.
It is intended to assist the driver by automati-
cally increasing the brake pressure during
emergency braking.
SSP254_048
Page 12 of 88
Downloaded from www.Manualslib.com manuals search engine
12
Occupant protection
Overview of system
G 256 N277G179G180
N153
K145
AIRBAGOFF
N95
N202
N154
N278
G 257
J533
N199
N201
J234
G 283G 284
E224
AUSEIN
AIRBAG
N131
N200
J393J526 T16
J220
J162
J285/K75
SSP254_029
Page 13 of 88

Downloaded from www.Manualslib.com manuals search engine
13
The system comprises driver/passenger air-
bags, front side airbags, optional rear side
airbags, SIDEGUARDS
®
, three point front seat
belts with ball tensioners and belt force limit-
ers, three point rear outer seat belts, centre
lap belt (for fixed rear seat bench), Isofix pre-
paration in rear of vehicle, and a total of 6
non-central accelerometers:
– 2 front impact crash sensors
– 2 driver/passenger side airbag crash sen-
sors, (in the B-pillar for side impact)
– 2 driver/passenger rear side airbag crash
sensors, (on the C-pillar for side impact) To complement the comprehensive body
modifications, occupant protection has been
improved through the further development of
the familiar 8.4 airbag system.
The new generation bears the designa-
tion 8.4 E, where the E stands for
"extended".
The position of the sensors is selected so that
they are installed as near as possible to the
outer structure of the vehicle.
This enables quicker deceleration detection in
the event of an impact.The external sensors deliver digitised acceler-
ation data to the airbag control unit, which is
then evaluated in the control unit and which
triggers the relevant restraint system compo-
nents.
Key
E224 Key switch for switching off
passenger’s side airbag
G179 Side airbag crash sensor, driver’s
side (B-pillar)
G180 Side airbag crash sensor, passenger’s
side (B-pillar)
G256 Crash sensor for rear side airbag,
driver’s side
G257 Crash sensor for rear side airbag,
passenger's side
G283 Front airbag crash sensor, driver’s
side
G284 Front airbag crash sensor,
passenger’s side
J162 Heater control unit
J220 Control unit for motronic
J234 Airbag control unit
J285 Control unit with display unit in
dash panel insert
J393 Central control unit for convenience
system
J526 Control unit for telephone /
telematics
J533 Diagnosis interface for data bus
(Gateway)K75 Airbag warning lamp
K145 "Airbag off" warning lamp,
passenger's side
N95 Airbag igniter, driver's side
N131 Airbag igniter 1, passenger's side
N153 Igniter for belt tensioner, driver's side
N154 Igniter for belt tensioner,
passenger's side
N199 Igniter for side airbag, driver’s side
N200 Igniter for side airbag, passenger's
side
N201 Igniter for rear side airbag,
driver’s side
N202 Igniter for rear side airbag,
passenger's side
N277 Igniter for airbag in B-pillar
(SIDEGUARD
®
), driver's side
N278 Igniter for airbag in B-pillar
(SIDEGUARD
®
), passenger's side
T16 Connector, 16-pin, diagnosis
connection
Page 14 of 88
Downloaded from www.Manualslib.com manuals search engine
14
Crash sensors for front airbag G283, 284
Both sensors for front impact detection func-
tion in conjunction with the crash sensor and
the safe sensor which are integrated into the
airbag control unit J234.
Deceleration load
Time [ms]
Vehicle rebound Impact
Triggering of belt tensioners
Triggering of front airbags
Front airbags inflated
Belt force limiter
response
Damping function
response in
the steering column
SSP254_063
SSP254_064
Upper body
Head
If a certain signal threshold is exceeded in the
front airbag crash sensor, a threshold reduc-
tion is activated in the airbag control unit,
which results in a shorter triggering time.
Occupant protection
SSP254_058
Page 15 of 88

Downloaded from www.Manualslib.com manuals search engine
15
Re-encoding of the airbag control unit is no
longer possible after the first crash data mes-
sage is stored.
Triggering is performed in two thresholds
depending upon the deceleration value:
– Threshold 1 = belt tensioners only
– Threshold 2 = belt tensioners and airbag(s)
Crash sensors for side airbags
G179, 180, 256, 257
In order to trigger the components of the
restraint system, two simultaneous impact
detection signals are required for the plausi-
bility check:
– from both opposing crash sensors
(B-pillar left with right and/or
(C-pillar left with right) and
– from the control unit internal crash sen-
sors.
The crash sensors are designed in such a way
that incorrect installation is excluded.
Airbag control unit J234
The warning lamp for airbag K75 is activated
continuously following a detected impact.
"CRASH DATA STORED" and the triggered
components are displayed with fault code
during fault memory readout.
Sensors and components to be replaced
following an accident, are listed in the
current workshop manual.
SSP254_059
Page 16 of 88
Downloaded from www.Manualslib.com manuals search engine
16
Occupant protection
Front belt attachment
Belt lock and strap fastenings are perma-
nently connected to the seat frame. Thus, in
conjunction with the seat belt height adjuster,
an optimal belt fitting can be achieved for
each seat position.
Deactivation of passenger airbag
Deactivation of the passenger airbag is only
possible via the key switch. In the Audi A4, the
passenger's side airbag is also deactivated.
Deactivation via the diagnostic tester is not
possible.
If a customer requires the deactivation func-
tion where a key switch is not fitted, this can
only be achieved by retrofitting the key switch
and airbag OFF lamp and by re-encoding of
the airbag control unit.
Front head restraints
In order to offer a high degree of occupant
protection in conjunction with the seat belt
and airbag, the front head restraints have
been supplemented by an integral locking
mechanism.
aa
aaa
a
SSP254_011
SSP254_102SSP254_101
Page 36 of 88
Downloaded from www.Manualslib.com manuals search engine
36
Front airbag crash sen-
sor, driver’s side G283
Vehicle electrical system
Electrical system
Control unit for
coolant fan,
Stage 1+2 J293Control unit
for ESP J104 Control unit for
telematics J499
Control unit for
mobile phone control
electronics J412
Front airbag crash
sensor, passen-
ger’s side G284
Control unit
for Motronic J220
Control unit for auto-
matic gearbox J217
Control unit for headlamp
range control J431Chip card
reader R99
Steering column
switch module J527
Battery
Control unit with
display in dash panel
insert J285