key battery AUDI A8 2003 D3 / 2.G Technical Features Manual

[x] Cancel search | Manufacturer: AUDI, Model Year: 2003, Model line: A8, Model: AUDI A8 2003 D3 / 2.G
Pages: 96, PDF Size: 5.51 MB

Page 15 of 96

AUDI A8 2003 D3 / 2.G Technical Features Manual Downloaded from www.Manualslib.com manuals search engine 15
The wide range of sensors permits detection
not only of head-on collision and side impact,
but also of rear-end collisions. Use is made in

Page 16 of 96

AUDI A8 2003 D3 / 2.G Technical Features Manual Downloaded from www.Manualslib.com manuals search engine 16
15
J234
J655
1
2
E224
3
G283G284G179
N131
F138
N202N199N200N201N95
Key
E24 Driver side belt switch
E25 Front passenger side belt switch
E224

Page 42 of 96

AUDI A8 2003 D3 / 2.G Technical Features Manual Downloaded from www.Manualslib.com manuals search engine 42
Engine, Mechanics
Sequence of operations
1 Entry and start authorisation switch E415/entry and start authorisation button E408
2 Entry a

Downloaded from www.Manualslib.com manuals search engine 42
Engine, Mechanics
Sequence of operations
1 Entry and start authorisation switch E415/entry and start authorisation button E408
2 Entry and start authorisation control unit J518
The entry and start authorisation control
unit checks for authorisation – in the form
of information on selector slide position N
or P – from the automatic gearbox control
unit J217 and for brake application in the
case of a start signal from the entry and
start authorisation button E408.
3 Engine control unit J623 Application of selector slide position P/N or
"clutch pressed" information to the engine
control unit (separate interface) causes the
two starter relays J53 and J695 to be
actuated simultaneously. The relays then
switch terminal 50 for starter actuation.
The starter operates and cranks the engine.
On exceeding a deﬁned engine speed, the
engine control unit J623 recognises that
the engine has started and the relays are
deenergised (thus terminating starting
process).
As a safeguard, two relays are connected in
series. In the event of fusion welding of the
make contacts (relay remains closed
following deenergisation), the engine
control unit J623 can thus interrupt the
circuit (terminal 50) by way of the other
relay in each case.
The two relays are deenergised alternately
in order to ensure even make contact wear
(break spark) in both relays. The
deenergisation sequence alternates. The driver triggers a brief start signal
(min. 20 ms) by turning the ignition key to
start position or by pressing the entry and
start authorisation button E408.
If the start prerequisites have been
satisﬁed, the entry and start authorisation
control unit J518 transmits a start request
– terminal 50 ON – to the engine control
unit J623.
The entry and start authorisation control unit J518 also controls the terminal 15 and
terminal 75x circuits.
Relay operation is monitored and faults diagnosed by evaluating the alternating
deenergisation with the aid of the terminal
50R interface.
The terminal 50R interface represents a link
with terminal 50 and provides the engine
control unit J623 with feedback for start
control/diagnosis.
Automatically controlled starting is not
permitted in the event of undervoltage or a
system fault.
The engine can however be started
manually by way of corresponding start
signal actuation.
To relieve the load on the starter and
battery, the relay actuation time is
limited to approx. 10 seconds per starting
operation (automatic or manual starting).

Page 48 of 96

AUDI A8 2003 D3 / 2.G Technical Features Manual Downloaded from www.Manualslib.com manuals search engine 48
Selector lever/button kinematics
To prevent inadvertent shifting into selector
lever position "S", a change has been made to
the selector

Page 73 of 96

AUDI A8 2003 D3 / 2.G Technical Features Manual Downloaded from www.Manualslib.com manuals search engine 7374
A distinction is made between two air
conditioner unit versions
– 2-zone front and rear climate
control
– 4-zone front and rear

Downloaded from www.Manualslib.com manuals search engine 7374
A distinction is made between two air
conditioner unit versions
– 2-zone front and rear climate
control
– 4-zone front and rear climate
control
and three types of control and
display unit
– Air conditioner control panel with
no seat heating/ventilation
– Air conditioner control panel with
seat heating
– Air conditioner control panel with
seat heating and seat ventilation
(identiﬁed by part number index).
SSP282_099
Self-diagnosis
Fault diagnosis and measured value blocks
for air conditioner and seat heating system
can be read out by way of address words 08
"Air conditioner/heater electronics" and 28
"Rear climate control". The functions of and
exact procedure for self-diagnosis and
assisted fault-ﬁnding with VAS 5051 can be
found in the Heating/Air Conditioner
Workshop Manual for the relevant vehicle
model.
Operating principle
When the ignition is switched on, the
Climatronic control unit J255 starts up with
the same temperature, air distribution and
fresh-air blower speed settings etc. as were
applicable the last time the ignition was
switched off by way of the appropriate key or
using ﬁngerprint recognition.
If ﬁngerprint recognition has been
implemented, this has priority over key
recognition (refer also to SSP 287 – Audi A8 ´03
Electrical Components).
Personalised settings
The following settings can be made for each
climate control zone (front left, right and,
optionally, with 4-zone climate control rear left
and right):
– Left/right temperature
– Air ﬂow
– Left/right air distribution
– Left/right seat heating
– Left/right seat ventilation
– Operating modes (AUTO for driver and front
passenger, temperature-adjustable centre
vents, automatically controlled
recirculated-air mode, ECON)
The heated windscreen can be activated by
way of the air conditioner defrost button or
the air conditioner control unit automatically
switches on the electric heated windscreen if
the appropriate conditions are satisﬁed
(windscreen defrost or automatic mode on
cold starting).
The Climatronic J255 and heated windscreen
J505 control units communicate by way of the
LIN bus. The Climatronic control unit transmits
the speciﬁed windscreen heating power to the
heated windscreen control unit on the LIN bus.
Heating/Air Conditioner
Key recognition takes place in the case of
remote control (radio or key transponder),
with the driver identiﬁcation control unit
providing the Climatronic control unit J255
with the appropriate information by way of
the CAN bus.
The electrically heated windscreen is only
supplied with the amount of power which can
currently be drawn from the electrical system
without draining the battery. This is
monitored by the energy management
control unit J644.
As is the case with the Audi A4, the
windscreen is heated by applying voltage to a
metallic foil ﬁtted in the glass (refer to
SSP 213).
As in the Audi A4, the air conditioner
compressor is regulated as a function of load
and controlled externally by way of the
compressor regulating valve (refer to
SSP 240). The Climatronic control unit J255 is
connected to the convenience CAN, via
which diagnosis is also performed.
A manual air conditioning system is not
available.