2003 AUDI A8 engine

Downloaded from www.Manualslib.com manuals search engine 17
4567
G256G257E24E25
N198N251N252N153N154N196N197
G180
N251 Curtain airbag igniter, driver side
N252 Curtain airbag igniter,
front passenger side
Colour code
= Input signal
= Output signal
= Positive supply
= Earth
Additional signals
Battery A (positive)
Positive connection to starter B and
alternator C
Terminal 58s
Drive system CAN (High)
Drive system CAN (Low)
Crash signal
Airbag disabled warning lamp,
front passenger side K145
1
2
3
4
5
6
7
SSP282_069

Downloaded from www.Manualslib.com manuals search engine 18
Safety systems
2-stage front airbags
The 2-stage triggering of the front airbags
provides optimum restraint in crash
situations at around 30 km/h. There is a
separate firing pellet for each stage in the
driver's and front passenger's airbag. These
ignite successively at specified time intervals.
Ring airbag
Passenger Protection
SSP282_070
A so-called "ring airbag", which inflates like a
life belt, is used on the driver's side. This
radial inflation method affords particular
protection to drivers sitting very close to the
steering wheel. The centre of the steering
wheel does not move as the airbag unfolds
and is inflated in the form of a ring. A
rectangular fabric layer is additionally sewn
to three sides of the ring. One side is left free
to allow the airbag to slide over the non-
moving centre section of the steering wheel. This airbag design satisfies the requirements
of the latest American legislation and
involves compliance with biomechanical
values for so-called "Out Of Position" (OOP)
driver posture. If the driver's head or upper
part of the body is very close to the steering
wheel at the time of airbag unfolding (OOP),
this airbag concept can prevent serious
injury.

Downloaded from www.Manualslib.com manuals search engine 19
Front passenger's airbag deactivation
An optional feature of the Audi A8 ´03 is a new
airbag disabling key switch for the front
passenger's side E224.
Two resistance paths are integrated into this
switch to permit detection of individual faults.
A fault in the key switch is indicated by
flashing of the front passenger's side airbag
disabled warning lamp K145 located in the
centre console next to the hazard warning
switch.
Front knee airbags (USA)
SSP282_081
SSP282_114
The USA version of the Audi A8 ´03 is fitted
with driver's and front passenger's knee
airbags as standard, thus optimising driver
and front passenger movement in a crash
situation.In this way, severe impact in the knee zone is
avoided.
Knee airbags are required by legislation in the
USA.

Downloaded from www.Manualslib.com manuals search engine 20
Passenger Protection
Up-front sensors
For the first time, use is made in the
Audi A8 ´03 of so-called up-front sensors.
SSP282_072
Lateral acceleration sensors
Further acceleration sensors are
located at the B and C-pillars.
SSP282_073
Detection of rear-end collision
Rear-end collisions are detected by way of a
sensor in the airbag control unit J234 and a
plausibility function involving the driver's and
front passenger's front airbag crash sensors
G283 and G284.
These take the form of two additional front-
end acceleration sensors on the right and left
beneath the corresponding headlight.
C-pillar sensor B-pillar sensor

Downloaded from www.Manualslib.com manuals search engine 21
Active head restraints
The front seats of the Audi A8 ´03 are provided
with active head restraints.
With this system, the head restraints move
forwards in the event of a rear-end collision to
shorten the distance between head and
restraint.
SSP282_082
The danger of cervical vertebrae injury is
greatly diminished by reducing the relative
acceleration between shoulder and head.
In head-on collision situations, the mechanics
of centrifugal weight are neutralised.
Belt tensioners
Five belt tensioners are fitted as standard.
There is no centre belt tensioner if the rear
seats are electrically adjustable.

Downloaded from www.Manualslib.com manuals search engine 22
Passenger Protection
15 30
+
-
31
J644
J655
43
B
1
2
A
TerminalPinInput/outputDescription
30, battery A Input
(screw connection)U
bat. term. 30/battery
87 B Output
(screw connection)Output
Terminal 15 1 Input
(plug connection)Positive power supply,
interruptible
Vehicle earth 2 Input
(plug connection)Earth from
airbag control unit J234
Crash signal 3 Input
(plug connection)Crash signal from
airbag control unit J234
Diagnosis 4 Input
(plug connection)Diagnostic wire from
airbag control unit J234
Battery cut-off relay J655
The battery cut-off relay is a battery isolating
element designed to disconnect starter and
alternator power from the electrical system in
the event of a crash.
Block diagram
J644 Energy management control unit
J655 Battery cut-off relay
SSP282_076

Downloaded from www.Manualslib.com manuals search engine 23
Fitting location
The battery cut-off relay is located in front of
the battery.
Triggering
The airbag control unit J234 provides the
battery cut-off element with the triggering
command via a discrete wire.
Triggering of this element by the airbag
control unit causes a white panel to appear in
the element window instead of a copper coil.
Following isolation, the battery cut-off
element can be manually reset by way of the
yellow knob.
Control element test
The control element test in the airbag control
unit also triggers the battery cut-off relay. It
should be ensured that the relay is manually
reset, as otherwise the battery cannot be
charged.
SSP282_079
SSP282_077
SSP282_083
Reset knobWindow

Downloaded from www.Manualslib.com manuals search engine 24
Engine, Mechanics
200040006000
40
60
80
100
120
140
160
180
200
220
240
260
280 300
320
340 360380 400
420 440
460
Technical data
V8 4.2 l 5V engine
Engine code
letters: BFM
Capacity:
3
Bore: 84.5 mm
Stroke: 93.0 mm
Compression
ratio: 11 : 1
Power: 246 kW (335 hp)
at 6,500 rpm
Torque: 430 Nm at 3,500 rpm
Camshaft
adjustment
range: 22° CS advance
Valves: 5 per cylinder
Engine
management: ME7.1.1
Emission
standard: EU 4
Firing
order: 1 - 5 - 4 - 8 - 6 - 3 - 7 - 2
Capacities: 7.5 l engine oil (incl. filter)
Consumption: Urban: 17.5 - 17.6 l/100 km Non-urban: 8.7 - 8.8 l/100 km
Average: 11.9 - 12.0 l/100 km
Acceleration
0 - 100 km/h: 0 - 80 km/h – 4.8 s 0 - 100 km/h – 6.3 s
Fuel: Premium Plus Unleaded 98/95 RON
CS = Crankshaft
SSP282_002
SSP282_012
Engine speed [rpm]
P
ower [kW]
T
orq ue [Nm]
4,172 cm