2008 Alfa Romeo GT brake sensor

GETTING TO KNOW YOUR CAR
74
BRAKE PAD WEAR
With the brake pedal pressed, the display
will show message + symbol when front
brake pads are worn; in this case have them
changed as soon as possible.
IMPORTANTSince the car is fitted with
wear sensors for the front brake pads, when
changing them, check also the rear brake
pads.
SELESPEED
TRANSMISSION
FAILURE
(2.0 T.SPARK
Selespeed versions)
On versions with Selespeed transmission,
message + symbol are displayed when there
is a failure in the Selespeed transmission. In
the event of Selespeed transmission failure,
go as soon as possible to the nearest Alfa
Romeo Authorized Services and have the
system checked.
ENGINE CONTROL
SYSTEM FAILURE
(EOBD) (amber)
(upon request for versions/
markets where applicable)
In normal conditions, turning the ignition
key to MAR, the warning light turns on,
but it should go off when the engine has
started. The initial turning on indicates that
the warning light is working properly.
If the warning light stays on or turns on
when travelling (together with message +
symbol on the display):
glowing steadily- means a fault in the
supply/ignition system which could cause
high emissions at the exhaust, possible lack
of performance, poor handling and high con-
sumption levels. In these conditions it is pos-
sible to continue driving without however re-
quiring heavy effort or high speed from the
engine. Prolonged use of the car with the
warning light on may cause damages. Con-
tact Alfa Romeo Authorized Services as soon
as possible. The warning light goes off if the
fault disappears, but it is however stored by
the system;
SEAT BELTS NOT
FASTENED (red)
The warning light turns on glowing steadi-
ly with ignition key at MAR, when the dri-
ver’s seat belt is not fastened correctly.
INCOMPLETE DOOR
LOCKING
Message + symbol are displayed when
one or more doors or the bonnet are not
properly shut.
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GETTING TO KNOW YOUR CAR
135
Always take due care when braking on
bends, even with the help of the ABS.
The most important advice of all, howev-
er, is this:
When the ABS cuts in, and
you feel the pulsing on the
pedal, do not lighten the
pressure, but keep the pedal firm-
ly pressed with no fear; this way
you will stop in the least space
possible, compatibly with the con-
ditions of the road surface.
Following these instructions you will be
in the best braking condition under all cir-
cumstances.
IMPORTANTCars fitted with ABS may
only be fitted with the wheel rims, tyres and
brake linings of type and brand approved by
the Manufacturer.
The system is completed by the EBD (Elec-
tronic Brake Distributor) which distributes
the braking action through the control unit
and the ABS system sensors. The car is fitted with an
electronic braking distribu-
tor (EBD). If the
>andx
warning lights turn on simultane-
ously with the engine running, this
indicates an EBD system failure; in
this case with sharp braking the
rear wheels might lock too early,
with the possibility of skidding. Dri-
ving extremely carefully, go to the
nearest Alfa Romeo Authorised Ser-
vice to have the system checked.
The turning on of only the
>warning light with the
engine running normally in-
dicates a fault to the ABS system
only. In this case the braking sys-
tem is still efficient, though with-
out the aid of the anti-lock device.
Under these conditions perfor-
mance of the EBD system may be
reduced. In this case too, you are
advised to go immediately to the
nearest Alfa Romeo Authorised
Service to have the system checked
over, driving in such a way as to
avoid sharp braking.
If the low brake fluid lev-
el
xwarning light turns
on, stop the car immedi-
ately and contact the nearest Alfa
Romeo Authorised Service. Any
loss of fluid from the hydraulic sys-
tem will negatively affect the op-
eration of the braking system be it
of the conventional type or of the
type with ABS.
If the compact spare
wheel is used, operation of
the ABS system is cut off
and the
>warning light on the in-
strument cluster turns on.
IMPORTANTIf the battery is run down
the
>andxwarning lights might turn on
when starting the engine and go off after
starting. This should not be considered as
a fault but as a warning that during start-
ing the ABS is not active. The turning off
of the warning lights ensures normal system
operation.

GETTING TO KNOW YOUR CAR
136
VDC SYSTEM
(Vehicle Dynamics Control)
(on request for versions/
markets where applicable)
The VDC is an electronic system that con-
trols car stability, intervening on the driving
torque and braking the wheels in a differ-
entiated manner, in the lack of grip, it helps
to bring the car back to the correct direction.
When travelling the car is subjected to lat-
eral and longitudinal forces which can be
controlled by the driver as long as the tyres
offer adequate roadholding; when this falls
below the minimum level, the car begins
to divert from the course required by the dri-
ver.
Especially when travelling on an uneven
surface (such as paving, or due to the pres-
ence of water, ice or soil), changes in speed
(acceleration or braking) and/or course
(bends or the need to avoid obstacles) may
cause the tyres to lose grip. When the sensors detect the conditions
that would lead to skidding, the system in-
tervenes on the engine and on the brakes
producing a stabilising torque.
HOW THE VDC
SYSTEM WORKS
System is engaged automatically when the
car is started and cannot be switched off.
The basic components of the system are:
– an electronic control unit that process-
es the signals received from the various sen-
sors and brings about the most appropriate
strategy;
– a sensor that detects the position of the
steering wheels;
– four sensors that detect the turning
speed of each wheel;
– a sensor that detects rotation of the car
around its vertical axis;
– a sensor that detects lateral acceleration
(centrifugal force).
The heart of the system is the control unit,
which with the data supplied by the sensors
installed on the car calculates the centrifugal
forces generated when the car is cornering.
The yawing sensor, which originates from the
aeronautical industry, detects the rotations
of the car around its own vertical axis. The
centrifugal forces generated when the car
is cornering are detected by a highly sensi-
tive lateral acceleration sensor. The performance of the
system, in terms of active
safety should not induce
the driver to take pointless and un-
necessary risks. The style of dri-
ving must in any case always be
adapted to the conditions of the
road surface, visibility and traffic.
The responsibility for road safety
is always and in any case the dri-
ver’s.
System helps the driver to keep the car un-
der control in the event of a loss of tyre grip.
The forces induced by the system to con-
trol the loss of car stability always depend
on the grip between the tyre and the road
surface.