lock AUDI A4 2001 B5 / 1.G Technical Features Design And Function

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11
Luggage compartment lid
The luggage compartment lid should always
be operated via the radio remote control.
The lock cylinder for the luggage compart-
ment lid is integrated into the handle.
Emergency door locking
In the event of failure of the central locking,
e.g. due to power supply faults, each door can
be individually locked without using the lock
cylinder.
Firstly, with the door open, the cap must be
removed. Emergency locking is effected by
inserting the ignition key.
After the door has been closed, it is not possi-
ble to open it from the outside.
The door can be opened from the inside by
actuating the door release handle twice.
Continuous locking of luggage compartment
If the lock cylinder is in the horizontal posi-
tion with the key removed, the luggage com-
partment lid is no longer included in the
central locking system. Opening is then only
possible via the centre unlocking button of
the radio remote control.
When the lock cylinder is in the vertical posi-
tion, the lid is an integral part of the central
locking system.
Manual unlocking and opening
is effected by turning the key to the left.
In this position, it is not possible to remove
the key, which must subsequently be returned
to the vertical position.
Thus, it is ensured that the luggage compart-
ment lid is an integral part of the central lock-
ing system.
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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

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Crash signal processing
There are two separate crash signal outputs:
One crash signal is output via the conven-
tional wiring and triggers the following func-
tions:
– Transmitting an emergency call via the
control unit for telephone/telematics J526
(optional)
– unlocking the vehicle,
– Switch on interior light
(switch must be set to door contact),
– switching on hazard warning lights via the
central convenience electronics J393.
The auxiliary heater J162 (optional) is
switched off by the central convenience
electronics J393 via a CAN convenience
message.
The second crash signal output functions via
the convenience CAN bus, which switches off
the engine fuel supply via the engine control
unit J220.

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Brake assistant
Investigations in accident research have
shown, that the majority of drivers fail to ade-
quately actuate the brakes in an emergency
situation.
This results in insufficient brake pressure
being generated to achieve maximum vehicle
deceleration.
This lengthens the braking distance.During emergency braking, the brake assist-
ant aids the driver by increasing the brake
pressure automatically, to a level exceeding
the locking limit.
The ABS (
A
nti-lock
b
raking
s
ystem) is thus
quickly brought into the operating range,
which enables a maximum vehicle decelera-
tion to be achieved.
Brake servo pressure sensor G294 is used for
detection of emergency braking.
Time [t]
Pressure [p]

For this purpose, the pressure increase gradi-
ent (pressure build-up with respect to time) is
evaluated and, if necessary, the brake assist-
ant is activated.
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Emergency braking
Normal braking distance
Pressure sensor G294

Running gear
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• Phase 2
If the pressure determined by the driver falls
below a certain value after triggering of the
brake assistant, the system pressure is
restored to the pedal pressure determined by
the driver. The function of the brake assistant is
sub-divided into 2 phases:
• Phase 1
If the pressure increase gradient exceeds a
specified value (emergency braking), the ABS
return pump and the relevant solenoid valve
are activated by the ESP control unit and the
brake pressure is thus increased into the ABS
control range, in a similar manner to that of
the control system for an electronic differen-
tial lock.
The integral inlet and outlet valves in the
hydraulic modulator are no longer sim-
ply switched on/off, but are regulated
via supplied voltage.
This enables more precise control on
extremely slippery surfaces, e.g. ice.
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Time [t]
Brake pressure [p]
Brake pressure determined by an
experienced driver
Regulated brake pressure
(brake assistant)
Determined brake pressure
insufficient inexperienced driver Brake assistant activated Brake pedal unloaded Brake assistant
switches off
Phase 1Phase 2
ABS control
range

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Running gear
Brake fluid reservoir
The brake fluid reservoir is secured with an
additional screw.
The new maintenance opening in the brake
fluid reservoir enables the extraction of brake
fluid from both brake fluid chambers.
The new brake filler and bleeder unit
VAS 5234 must be used for this purpose.
Brake light switch
The fastening and adjustment of the brake
light switch are new.
The brake light switch is secured to the pedal
bracket via a bayonet fitting.
The position of the push rod is adjusted for
the basic setting.
For this purpose, the brake light switch must
be released by turning it anti-clockwise.
The push rod catch is released simultane-
ously via the locking lug.
The push rod is now free and can be adjusted
without risk of damage.
The push rod is pulled out to the stop for the
basic setting.
The brake light switch can now be inserted
into the pedal bracket and secured by turning
clockwise. At the same time, the push rod
catch is locked automatically by means of the
locking lug.
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Maintenance openingFastening screw
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Electrical system
Setting buttons for digital clock,
date and instrument illuminationAuto-check system
Call-up button for
service interval
indicatorReset button for trip
recorder
Dash panel insert
There are two dash panel insert versions:
– "lowline"
– "highline"
The "highline" version is equipped with a
high-quality colour display for the driver infor-
mation system and is installed in vehicles
with navigation systems as well as telematics.The dash panel insert of the new Audi A4 is
equipped with
– the gateway for linking the three data bus
systems: drive, convenience, information
– and the immobiliser III.
Cruise control system ON
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In order to ensure good signal reception for
the radio clock, the receiver is installed in the
rear bumper bar. User prompt in the centre display via the con-
trol switch in the centre console, is only avail-
able in vehicles with
– navigation system ("highline" version only)
and/or
– telematics and/or
– auxiliary heater and/or
– tyre pressure monitoring.
The optional driver information system
includes the following functions:
– radio clock
– auto-check system
– on-board computer.
The km range is indicated in the basic ver-
sion.
Ear
th
Radio signal
+ 5
V

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A further innovation is the display of the max-
imum and minimum engine oil levels in the
measured value block after the most recent
service operation.
The adaptation of the mileage/kilometre read-
ing after replacement of the dash panel
insert, is possible (several attempts) up to a
recorded distance of 5 km after installation. The dash panel insert checks the plausibility
– of both fuel gauge senders in quattro
vehicles
– as well as the terminal 15 input signal.
Due to the gateway function of the dash panel
insert, the communication with the individual
control units connected to the CAN data bus
is checked during diagnosis.
Communication faults are entered into the
fault memory. The current status can be read
in the measured value blocks.
Control unit with
display unit in
dash panel insert J285
Control unit for steering
column electronics J527
Ignition lock D Convenience data
bus
Terminal 15
Diagnostics
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Electrical system
Steering column switch
module
Due to the compact design of the newly
developed steering column switch module, it
was possible to minimise the amount of wir-
ing necessary and the space requirements.
A self-diagnosis facility for the steering col-
umn switch is now available with new switch
module.
The steering column switch module consists
of the following components:
– Turn signal switch
– Wiper switch with interval potentiometer
– Separate steering column switch cruise
control system operation
– Coil spring for diver's airbag
– Steering angle sensor for ESP
– Steering column electronics for signal con-
version and processing of drive and con-
venience CAN BUS J527
In addition, the steering column electronics
register the ignition switch signals.
Furthermore, the control buttons for multi-
function and "tiptronic" steering wheel are
registered via the steering wheel electronics
module.
Steering column switch
Detection of the respective switch positions is
effected via voltage coding, using various
resistance values in the relevant position. The
steering column electronics evaluates this
switch information and transmits it, via the
convenience CAN BUS, to the vehicle electri-
cal system control unit J519.
Cruise control system (CCS)
For ergonomic reasons, the control switch for
the cruise control system is located on the
left side of the steering column, below the
turn signal lever.
Warning lamp K31 in the dash panel insert
illuminates when the CCS is in control mode.
The modified operation of the CCS Steering
column switch function is described in the
Owner's Manual.
Cruise control
system E45
Ignition
steering lock Steering column
electronics J527
Turn signal
switch E2
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