2017 Seat Leon 5D brake

Driver assistance systems
When the ACC function is active, the vehicle
tr av
el
s at a set speed and distance from the
vehicle ahead. Both speed and distance can
be changed at any time.
Disconnecting and deactivating the ACC
To disconnect the ACC move the lever to the 0 position
›››
Fig. 211
(en
gaged). An ACC
deactivated message appears and the
function is totally deactivated.
If you do not wish to disconnect the ACC, just
to switch it temporarily to inactive mode
(Standby), move the third lever to position 3›››
Fig. 211 or pre s
s the brake pedal.
It will also switch to inactive mode (Standby)
if the vehicle is stopped and the driver door
is opened.
Adjusting the default distance level at the
start of your journey.
In wet road conditions, you should always set
a larger distance with regard to the vehicle in
front than when driving in dry conditions.
The following distances can be preselected:
● Very short
● Short
● Media
● Long
● Very long In the Easy Connect system you can adjust
the dis
t

ance level that will be applied when
the ACC is connected using the  button
and the S
ET
TINGS and
Driv
er a
s
sistance function
b utt
on
s ›››
 page 33.
Changing the driving profile
In vehicles with SEAT Drive Profile , the driving
profile selected can have an influence on the
ACC’s acceleration and braking behaviour
››› page 230.
In vehicles without SEAT Drive Profile , the be-
haviour of the ACC can also be affected by se-
lecting any of the following drive profiles in
the Easy Connect system:
● Normal
● Sport
● Eco
● Convenience
In this c
ase, you should access the ACC set-
tings using the  button and the
S
ET
TINGS >
Driv er a
s

sistance >
A
C
C function buttons
› ›
›
 page 33.
The following conditions may lead the ACC
not to react:
● If the accelerator is pressed.
● If there is no gear engaged.
● If the ESC is controlling. ●
If the driver i
s not wearing his/her seat
belt.
● If several brake lights of the vehicle or elec-
trically
connected trailer are damaged.
● If the vehicle is reversing.
● Driving faster than 210 km/h (150 mph).
Driver mes
sages
 ACC not available
The system can no longer continue to guar-
antee safe vehicle detection and will be de-
activated. The sensor has lost its setting or is
damaged. Take the vehicle to a specialised
workshop and have the fault repaired.  ACC and Front Assist: cur-
rently not available. No sensor
vision
This message will be displayed to the driver if
the radar sensor's vision is impaired due, for
example, to leaves, snow, heavy fog or dirt.
Clean the SEAT badge ››› Fig. 210.
 ACC: currently not available.
Gradient too steep
The maximum road slope has been excee-
ded, hence safe ACC operation cannot be
guaranteed. The ACC cannot be switched on.  ACC: only available in D, S
or M
Select the D/S or M position on the selector
lever. »
219Technical data
Advice
Operation
Emergencies
Safety

Operation
 ACC: parking brake applied
The A C
C is deactivated if the parking brake is
applied. The ACC is available once again after
the parking brake is released.
 ACC: currently not available.
Intervention of stability con-
trol
The message for the driver is displayed when
the electronic stability control (ESC) inter-
venes. In this case, the ACC is automatically
switched off.  ACC: Take action!
The message for the driver is displayed if,
when the vehicle starts up on a hill with a
mild slope, the vehicle rolls back even al-
though the ACC is activated. Apply the brake
to stop the vehicle from moving/colliding
with another vehicle.  ACC: speed limit
The message for the driver is displayed if, in
vehicles with manual gearbox, the current
speed is too low for the ACC mode.
The speed to be stored must be at least
30 km/h (18 mph). The speed limiter
switches off if the speed falls below 20 km/h
(12 mph).  ACC: available as of the 2nd
gear The ACC is operational as of the 2nd gear
(manual g
earbox).
 ACC: engine speed
The message for the driver is displayed if,
when the ACC accelerates or brakes, the driv-
er does not shift up or down a gear in time,
which means exceeding or not reaching the
permissible engine speed. The ACC switches
itself off. A buzzer warning is heard.  ACC: clutch pressed
Vehicles with a manual gearbox: pressing the
clutch pedal for longer abandons control
mode. Door open
Vehicles with automatic gearbox: the ACC
cannot be activated with the vehicle station-
ary and the door open. WARNING
There is a danger of rear collision when the
minimum dis t

ance to the vehicle in front is
exceeded and the speed difference between
both vehicles is so great that a speed reduc-
tion by the ACC will not suffice. In this case
the brake pedal should be applied immedi-
ately.
● The ACC may not be able to detect all situa-
tions pr
operly.
● “Stepping” on the accelerator may cause
the ACC
not to intervene in braking. Driver braking will have priority over intervention by
the speed c
ontr

ol or adaptive cruise control.
● Always be ready to use the brakes!
● Observe country-specific provisions gov-
erning ob
ligatory minimum distances be-
tween vehicles. Note
● The pr ogrammed s

peed is erased once the
ignition or the ACC are switched off.
● When the traction control system (ASR) is
deactivat
ed during acceleration or else the
ESC is activated in Sport* Mode
( ››› page 120), the ACC switches off automati-
cally.
● In vehicles with the Start-Stop system, the
engine swit
ches off automatically during the
ACC stopping phase and restarts automatical-
ly to begin driving. 220

Driver assistance systems
Function for preventing overtaking in
an in s
ide l
aneFig. 213
On the instrument panel display:
A C
C

active, vehicle detected in an outer lane. The adaptive cruise control (ACC) has a func-
tion th
at
help

s avoid overtaking while driving
in inside lanes at certain speeds.
If another vehicle is detected travelling at a
slower speed in an outer lane, it is displayed
on the multifunction display ››› Fig. 213.
To avoid overtaking while driving in an inside
lane the system will gently brake, and in ac-
cordance with the speed will prevent the car
from overtaking. The driver can override this
function at any time. Deactivating the Adaptive Cruise Con-
trol

ACC temporarily in certain situa-
tions In the following situations the Adaptive
Crui
se C

ontrol (ACC) should be deactivated
due to the system's limitations ››› :
● When changing lanes, on tight bends and
rou nd

abouts, in acceleration and decelera-
tion lanes on motorways or in sections with
road works to prevent involuntary accelera-
tion to reach the programmed speed.
● When going through a tunnel, as operation
cou l

d be affected.
● On roads with several lanes, when other ve-
hicle
s are driving more slowly in the overtak-
ing lane. In this case, slower vehicles will be
overtaken on the right.
● In case of heavy rain, snow or spray, as the
vehicl
e in front might not be detected proper-
ly or, in certain circumstances, might not be
detected at all. WARNING
If the ACC does not switch off in the situa-
tions de

scribed, serious accidents and inju-
ries may occur.
● Always switch off the ACC in critical situa-
tions. Note
If you do not switch off the ACC in the afore-
mentioned sit uation

s, you may commit a le-
gal offence. 221
Technical data
Advice
Operation
Emergencies
Safety

Operation
Special driving situations Fig. 214
(A) Vehicle on a bend. (B) Motorcy-
c li
s
t ahead out of range of the radar sensor. Fig. 215
(C) Vehicle changing lanes. (D) One
v ehic
l

e turning and another stationary. The adaptive cruise control (ACC) has certain
ph
y
s

ical limitations inherent in the system.
For example, certain reactions of the ACC, in
certain circumstances, may be unexpected or
come late from the driver's point of view. So
pay attention in order to intervene if necessa-
ry.
For example, the following traffic situations
call for the utmost attention:
Starting driving after a stopping phase (only
vehicles with automatic gearbox)
After a stopping phase, the ACC may begin
driving automatically when the vehicle in
front drives off ››› .When the ACC halts the vehicle (e.g. traffic
j
am), the in
s

trument panel display shows the
ACC ready to start message. If the ve-
hicle ahead drives off again, the ACC will also
do so automatically.
If the vehicle ahead does not drive off again,
the vehicle can be kept indefinitely in the
ACC ready to start status by operating
the third lever repeatedly towards position 2
› ››
Fig. 211
or b
y pressing the brake pedal.
If the Press the brake message is shown
on the instrument panel, press the brake. If
you do not, an acoustic warning will be heard
and the ACC will switch to inactive mode
(Standby). At this point, the vehicle may be-
gin to move towards the stopped vehicle
ahead ››› .
Ov er
t

aking
When the turn signal lights up before the ve-
hicle begins an overtaking manoeuvre, the
ACC accelerates the vehicle automatically
and thus reduces the distance from the vehi-
cle in front.
When the vehicle enters the overtaking lane,
if the ACC does not detect another vehicle in
front, it accelerates until it reaches the pro-
grammed speed and maintains it.
System acceleration can be interrupted at
any time by pressing the brake or moving the
third lever backwards ››› page 218.
222

Driver assistance systems
Driving through a bend
On ent erin
g or e
xiting bends, the radar sen-
sor may no longer determine the vehicle in
front or react to a vehicle in the adjacent lane
››› Fig. 214 A. In these situations the vehicle
may brake unnecessarily or fail to react to re-
act to the vehicle in front. In this case, the
driver has to intervene by accelerating or in-
terrupting the braking process by applying
the brake or pushing the third lever back-
wards ››› page 218.
Driving in tunnels
When driving through tunnels the radar sen-
sor may be limited. Switch off the ACC in tun-
nels.
Narrow or misaligned vehicles
The radar sensor can only detect narrow or
misaligned vehicles when they are within
range ››› Fig. 214 B. This applies particularly
to narrow vehicles such as motorbikes. In
these cases, you should brake as necessary.
Vehicles with special loads and accessories
Special loads and accessories of other vehi-
cles that jut out over the sides, backwards or
over the top may be out of the ACC's range.
Switch off the ACC when driving behind vehi-
cles with special loads and accessories or
when overtaking them. In these cases, you
should brake as necessary. Other vehicles changing lanes
Vehicl
es changing lanes a short distance
away from your own can only be detected
when they are within range of the sensors.
Consequently, the ACC will take longer to re-
act ››› Fig. 215 C. In these cases, you should
brake as necessary.
Stationary vehicles
The ACC does not detect stationary objects
while driving, such as traffic tails or damaged
vehicles.
If a vehicle detected by the ACC turns or
moves over and there is a stationary vehicle
in front of it, the ACC will not react to it
››› Fig. 215 D. In these cases, you should
brake as necessary.
Vehicles driving in the opposite direction
and vehicles crossing your path
The ACC does not react to vehicles approach-
ing from the opposite direction or vehicles
crossing your path.
Metal objects
Metal objects, e.g. rails on the road or sheets
used in road works, can confuse the radar
sensor and cause the ACC to react wrongly. Factors that may affect how the radar sensor
operate
s
If laser sensor operation is impaired, due to
heavy rain, spray, snow or mud, the ACC is
deactivated temporarily. The relevant text
message will appear in the dash panel dis-
play. If necessary, clean the radar sensor.
When the radar sensor begins to operate
properly again, the ACC will automatically be
available again. The message on the instru-
ment panel screen will switch off and the ACC
will be reactivated again.
ACC operation may be affected by a strong ra-
dar reverse reflection, for example in a closed
car park.
Trailer mode
When driving with trailer the ACC controls
less dynamically.
Overheated brakes
If the brakes overheat, for example after
abrupt braking or in long and steep slopes,
the ACC may be deactivated temporarily. The
relevant text message will appear in the dash
panel display. In this case, adaptive cruise
control cannot be activated.
Adaptive cruise control can be reactivated
once brake temperature has cooled suffi-
ciently. The message will disappear from the
instrument panel display. If the message ACC
not available remains on for quite a long »
223
Technical data
Advice
Operation
Emergencies
Safety

Operation
time it means that there is a fault. Contact a
s pec
i
alised workshop. SEAT recommends vis-
iting a SEAT dealership. WARNING
If you do not heed the Press the brake
mes s

age, the vehicle may initiate an involun-
tary movement and could crash into the vehi-
cle ahead. In any event, before driving off,
check that the road is clear. The radar sensor
may not detect obstacles on the road. This
could cause an accident and serious injuries.
If necessary, apply the brake. Lane Assist system*
Intr oduction Fig. 216
In the windscreen: field of vision of
the Lane As s
i

st system camera. Using the camera located in the windscreen,
the Lane As
s
i

st system detects the possible
lines dividing the lanes. When the vehicle in-
voluntarily approaches a dividing line it has
detected, the system notifies the driver with
a corrective steering movement . The purpose
is not only to warn the driver, but also to
keep the vehicle inside the lane. This move-
ment can be over-regulated at any time.
No warning is produced with the turn signals
activated, given that the Lane Assist system
understands that a lane change is required. Indications on the display and lamps Fig. 217
On the instrument panel display: In-
dic ation on the Lane As
s

ist system display
(example 1). 224

Operation
Self-deactivation: the Lane As s
i st system can
be automatically deactivated if there is a sys-
tem malfunction. The control lamp
disappears.
Hands-Off Function
● In the absence of steering wheel activity
the syst
em alerts the driver with acoustic sig-
nals and a text message on the dash panel
asking to actively take over the steering.
● If the driver does not react to this, the sys-
tem also al
erts the driver with a little shaking
motion through the brakes and, if the vehicle
has it, activates the Emergency Assist func-
tion ››› page 228.
● In vehicles without Emergency Assist, the
adaptiv
e lane guidance function will be disa-
bled after the corresponding warnings to the
driver.
The lane assist system is active but it is not
available (the control lamp is lit up yellow)
● When driving at speeds below 65 km/h (38
mph).
● When the Lane Assist system does not de-
tect the div
iding lines of the road. For exam-
ple, in the event warnings indicating road
works, and snow, dirt, moisture or reflec-
tions.
● When the radius of a curve is too small.
● When no road markings can be seen. ●
When the dist
ance to the next marking to
too great.
● When the system does not detect any clear
and active st
eering movement during a long
period of time.
● Temporarily, in the event of very dynamic
driving s
tyles.
● If a turn signal is activated.
● With the stability control system (ESC) in
Sport
mode or switched off.
Switching off the Lane Assist system in the
following situations
Due to the limits of the Lane Assist system,
switch it off in the following situations:
● When more attention is required of the
driver
● When drivin

g in a sporty style
● In unfavourable weather conditions
● On roads in poor condition
● In areas of road works WARNING
The intelligent technology in the Lane Assist
sys t

em cannot change the limits imposed by
the laws of physics and by the very nature of
the system. Careless or uncontrolled use of
the Lane Assist system may cause accidents
and injury. The system is not a replacement
for driver awareness. ●
Alw a

ys adapt your speed and the distance
to the vehicles ahead in line with visibility,
weather conditions, the condition of the road
and the traffic situation.
● Always keep your hands on the steering
wheel so it c
an be turned at any time.
● The Lane Assist system does not detect all
roa
d markings. The road surfaces, road struc-
tures or objects in poor condition can be in-
correctly detected as road markings under
certain circumstances by the Lane Assist sys-
tem. In such situations, switch the Lane As-
sist system off immediately.
● Please observe the indications on the in-
strument p
anel and act as is necessary.
● Always pay attention to the vehicle's sur-
roundin
gs.
● When the area of vision of the camera be-
comes
dirty, covered or is damaged, the Lane
Assist system function can be affected. CAUTION
In order to avoid influencing the operation of
the sys t

em, the following points must be tak-
en into account:
● Regularly clean the area of vision of the
camera and k
eep it in a clean state, without
snow or ice.
● Do not cover the area of vision of the cam-
era.
● Check

that the area of vision of the wind-
scr
een camera is not damaged. 226

Driver assistance systems
Note
● The Lane Ass i
st system deactivates when
driving below 60 km/h (37 mph).
● The lane departure warning system has
been exc
lusively developed for driving on
paved roads only.
● If the Lane Assist system does not work as
desc
ribed in this chapter, do not use it and
contact a specialised workshop.
● Before starting a journey, verify that the
field of
vision of the camera is not covered
››› Fig. 216.
● Always keep the field of vision of the cam-
era cl
ean.
● If there is a fault in the system, have it
check
ed by a specialised workshop. Traffic Jam Assist
R el
at

ed video Fig. 219
Safety Description and operation
Traffic Jam Assist helps the driver keep the
car w
ithin its

lane and to move in convoy in
case of traffic congestion or slow traffic.
Traffic Jam Assist is an additional function of
Lane Assist ››› page 224 and combines Lane
Assist functions with Adaptive Cruise Control
(ACC) ››› page 214. Therefore, it is essential
that you read these two chapters carefully
and note the limitations of the systems and
the information about them.
Operation of Traffic Jam Assist
At speeds of below 60 km/h (40 mph), Traffic
Jam Assist can maintain a (temporary) dis-
tance preset by the driver with respect to the
vehicle ahead and help stay within the lane
››› .
T o do thi
s, the sy

stem automatically controls
the accelerator, brakes and steering, and
slows the vehicle, stopping it fully if neces-
sary, when faced with a vehicle in front that
has stopped. It automatically moves off again
when the vehicle ahead moves.
Traffic Jam Assist is designed only for use on
motorways and wide roads. Therefore, never
use it in city traffic. Technical requirements for using Traffic Jam
Assi

st
● Lane departure warning must
be activated:
 button > SETTINGS > Driver as-
sistance > Lane departure warning
(Lane Assist) › ›
›
 page 33.
● The Lane Centring Guide must be activated:
 button > SETTINGS > Driver as-
sistance > Lane departure warning
(Lane Assist)
● Adaptive Cruise Control (ACC) must be con-
nect ed and activ
e ›

›› page 218.
● The speed must be below 60 km/h
(38 mph).
Traffic

Jam Assist is not active (the Lane As-
sist control light turns yellow)
● If any of the conditions mentioned on
page 227, T
echnical requirements for using
Traffic Jam Assist are no longer met.
● If any of the conditions required for opera-
tion of the Lane Ass
ist are not met
››› page 224.
● If any of the conditions necessary for the
adaptiv
e cruise control (ACC) to work are no
longer fulfilled ››› page 214.
Situations in which Traffic Jam Assist must
be switched off
Due to the limitations of the system, Traffic
Jam Assist must always be switched off in the
following situations: »
227
Technical data
Advice
Operation
Emergencies
Safety