148 Intelligent technology
Intelligent technology Notice about data
recorded by vehicle
control modules
Your vehicle is not equipped with an Event Da
ta Recorder (EDR), installed by some manu
facturers fo r the express purpose of capturing
data for retrieval after an accident or crash
event . EDR's are sometimes called "crash re
corders".
Some state laws restrict the retrieval or down
loading of data stored by EDR's that were in
stalled in a vehicle for the express purpose of
retrieving data after an accident or crash
event without the owner's consent.
A lthough your vehicle is not equipped with an
EDR, it is equipped with a number of electron
ic control modules for various vehicle systems
such as, for example, engine function, emis
sion control, as well as for the airbags and
safety belts .
These electronic control modules also record
vehicle-related data during normal vehicle op
eration for diagnostic and repair purposes.
The recording capacity of the electronic con
trol modules is limited to data (no sound is re
corded) and only a small amount of data is ac
tually recorded over a very limited period of
time and stored when a system fault or other
condition is sensed by a control unit. Some of
the data then stored may relate to vehicle
speed, direction, braking as well as restraint
system use and performance in the event of a
crash or other condition. Stored data can only
be read and downloaded with special equip
ment.
Electronic Stabilization
Program (ESP)
General
The Electronic Stability Program increases
driving stability.
With ESP, control over the vehicle is increased
in situations when the vehicle is close to the
limits of grip, such as during acceleration and
in curves . ESP reduces the risk of skidding and
improves vehicle stability under all road con
ditions.
It operates at all speeds.
The Anti -Lock Brake System (ABS), Electronic
Differential Lock (EDS) and Anti-Slip Regula
tion System (ASR) are integrated in the Elec
tronic Stability Program .
How ESP works
The ESP control unit processes the following
data from high-sensitive sensors : the rota
tional speed of the vehicle about its vertical
axis , fore-and-aft and lateral acceleration
forces, brake pressure and steering angle.
Using steering angle and vehicle speed, the
direction the driver wishes to travel is deter
mined and continuously compared with actual
vehicle behavior. If the two do not match, for
example when the vehicle begins to skid, ESP
brakes the appropriate wheel automatically.
The vehicle is stabilized again by the forces
acting on the wheel during braking. With an
oversteering vehicle (tendency for the rear end to skid out of the curve), the brake appli
cation is mainly at the front wheel on the out
side of the curve, with an understeering vehi
cle (tendency to run wide in the curve) at the
rear wheel on the inside of the curve or addi
tionally at the other wheels as needed. This
brake application is accompanied by noises.
ESP works in conjunction w ith ABS
~ page 153. If there is malfunction in the
ABS, ESP is also inoperative.
