2015 Seat Leon 5D alternator

Operation
A cold engine consumes a disproportionate
amou nt
of
fuel. The engine reaches its work-
ing temperature after about four kilometres
(2.5 miles), when fuel consumption will re-
turn to a normal level.
Check tyre pressure
Always make sure the tyres are inflated to the
correct pressures ››› page 256 to save fuel. If
the pressure is below half bar, fuel consump-
tion may increase by 5%. Due to the greater
rolling resistance, under-inflation also increa-
ses tyre wear and impairs handling.
Do not use winter tyres all year round as they
increase fuel consumption by up to 10%.
Avoid carrying unnecessary loads
Given that every kilo of extra weight will in-
crease the fuel consumption, it is advisable
to always check the luggage compartment to
make sure that no unnecessary loads are be-
ing transported.
Since the luggage rack increases the aerody-
namic drag of the vehicle, you should remove
it when not needed. This will save, at a speed
of 100-120 km/h (60-75 mph), 12% of fuel.
Save electrical energy
The engine drives the alternator, thereby gen-
erating electricity. This implies that any in-
crease in power consumption also increases
fuel consumption! For this reason, switch off any unneeded electrical devices. Devices that
use a lot of
electricity includes the blower at
a high setting, the rear window heating or
the seat heating*. Driver assistance systems
Br ak
in
g and stability systems
Electronic Stability Control (ESC) The ESC helps to improve safety. It reduces
the tendency
t

o skid and improves the stabil-
ity and roadholding of the vehicle. The ESC
detects critical handling situations, such as
vehicle understeer or oversteer, or wheelspin
on the driving wheels. It stabilises the vehi-
cle by braking individual wheels or by reduc-
ing the engine torque. The warning lamp will
flash on the instrument panel when the ESC
is intervening .
ESC includes the Anti-lock brake system
(ABS), the brake assist system, the traction
control system (ASR), electronic differential
lock (EDL), electronic self-locking*, selective
torque control* and tractor-trailer sway miti-
gation*. ESC also helps stabilise the vehicle
by changing the torque.
Anti-lock brake system (ABS)
ABS prevents the wheels from locking up un-
der braking until the vehicle has reached a
virtual standstill. You can continue to steer
the vehicle even when the brakes are on full.
Keep your foot on the brake pedal and do not
pump the brakes. You will feel the brake ped-
al pulsate while the ABS is working.
178

Advice
distribution of electrical energy. This signifi-
c antly
impr
oves reliability when starting the
engine, and also prolongs the useful life of
the battery.
The main functions incorporated in the power
management system are battery diagnosis,
residual current management and dynamic
power management.
Battery diagnosis
The battery diagnosis function constantly
registers the condition of the battery. Sen-
sors detect the battery voltage, battery cur-
rent and battery temperature. This enables
the system to calculate the current power lev-
el and charge condition of the battery.
Residual current management
The residual current management reduces
power consumption while the vehicle is
parked. It controls the supply of power to the
various electrical devices while the ignition is
switched off. The system takes the battery di-
agnosis data into consideration.
Depending on the power level of the battery,
switch off the individual electrical devices
one after the other to prevent the battery
from losing too much charge and to ensure
that the engine can be started reliably. Dynamic power management
While the
vehicle is moving, this function dis-
tributes the available power to the various
electrical devices and systems according to
their requirements. The power management
ensures that on-board systems do not con-
sume more electrical power than the alterna-
tor can supply, and thus maintains the maxi-
mum possible battery power level. Note
● Neither is the po

wer management system
able to overcome the given physical limits.
Please remember that the power and useful
life of the battery are limited.
● When there is a risk that the vehicle will
not st
art, the alternator power failure or low
battery charge level warning lamp will be
shown  ››› page 108. Flat battery
Starting ability has first priority.
Shor
t
trip

s, city traffic and low temperatures
all place a heavy load on the battery. In these
conditions a large amount of power is con-
sumed, but only a small amount is supplied.
The situation is also critical if electrical devi-
ces are in use when the engine is not run-
ning. In this case power is consumed when
none is being generated. In these situations you will be aware that the
power m

anagement system is intervening to
control the distribution of electrical power.
When the vehicle is parked for long periods
If you do not drive your vehicle for a period of
several days or weeks, the power manage-
ment will gradually shut off the electrical de-
vices one by one or reduce the amount of cur-
rent they are using. This limits the amount of
power consumed and helps to ensure relia-
ble starting even after a long period. Some
convenience functions, such as remote vehi-
cle opening, may not be available under cer-
tain circumstances. These functions will be
restored when you switch on the ignition and
start the engine.
With the engine switched off
For example, if you listen to the sound sys-
tem with the engine switched off the battery
will run down.
If the energy consumption means there is a
risk that the engine will not start, a text will
appear in vehicles with a driver information
system*.
This driver indicator tells you that you must
start the engine so that the battery can re-
charge.
240

Checking and refilling levels
When the engine is running
A lthough the alt
ern
ator generates electrical
power, the battery can still become dis-
charged while the vehicle is being driven.
This can occur when a lot of power is being
consumed but only a small amount supplied,
especially if the battery is not fully charged
initially.
To restore the necessary energy balance, the
system will then temporarily shut off the elec-
trical devices that are using a lot of power, or
reduce the current they are consuming. Heat-
ing systems in particular use a large amount
of electrical power. If you notice, for instance,
that the seat heating* or the rear window
heater is not working, they may have been
temporarily switched off or regulated to a
lower heat output. These systems will be
available again as soon as sufficient electri-
cal power is available.
You may also notice that the engine runs at a
slightly faster idling speed when necessary.
This is quite normal, and no cause for con-
cern. The increased idling speed allows the
alternator to meet the greater power require-
ment and charge the battery at the same
time. Checking and refilling levels
Fi l
lin
g the tank
Filling up Read the additional information carefully
›› ›

 page 51
If the automatic filler nozzle is operated cor-
rectly, it will switch itself off as soon as the
fuel tank is “full”. Do not try to put in more
fuel after the nozzle cuts out, as this will fill
the expansion chamber in the fuel tank.
The correct fuel grade for your vehicle is giv-
en on a sticker on the inside of the fuel tank
flap. Further notes on fuel can be found at
››› page 243.
The capacity of your vehicle's fuel tank is giv-
en in ›››
 page 51.
Vehicles with natural gas engines and hy-
brids
Every 6 months it is necessary to run on pet-
rol until the control lamp switches off  and
then the tank must be refilled. This is neces-
sary to ensure that the system works proper-
ly, as well as the fuel quality required for driv-
ing with petrol. WARNING
Fuel is highly flammable and can cause seri-
ous b

urns and other injuries.
● Do not smoke when filling the fuel tank or a
canis
ter. Naked flames are forbidden in the
vicinity due to the risk of explosion.
● Observe legislation governing the use,
stor
age and carrying of a spare fuel canister
in the vehicle.
● For safety reasons we do not recommend
carry
ing a spare fuel canister in the vehicle.
In an accident the canister could be damaged
and could leak.
● If, in exceptional circumstances, you have
to carr
y a spare fuel canister, please observe
the following points:
– Never fill fuel into the spare fuel canister
if it is inside or on top of the vehicle. An
electrostatic charge could build up during
filling, causing the fuel vapour to ignite.
Danger of explosion. Always place the
canister on the ground to fill it.
– Insert the filling nozzle as far as possible
into the spare fuel canister.
– If the spare fuel canister is made of met-
al, the filling nozzle must be in contact
with the canister during filling. This
helps prevent an electrostatic charge
building up.
– Never spill fuel in the vehicle or in the
luggage compartment. Fuel vapour is ex-
plosive. Risk of fatal accident! » 241
Technical data
Advice
Operation
Emergencies
Safety

Checking and refilling levels
●
Tak e c
are not to cause short circuits in the
electrical system, especially when working
on the battery.
● If working inside the engine compartment,
remember that, ev
en when the ignition is
switched off, the radiator fan may start up au-
tomatically, and therefore there is a risk of in-
jury.
● Never cover the engine with additional in-
sul
ating materials such as a blanket. Risk of
fire!
● Do not unscrew the cap on the coolant ex-
pans
ion tank when the engine is hot. The
cooling system is under pressure.
● Protect face, hands and arms by covering
the cap with a l
arge, thick rag to protect
against escaping coolant and steam.
● If it is necessary to work in the engine com-
partment
while the engine is running, the ro-
tating components (for example, poly-V belt,
alternator, radiator fan) and the high voltage
ignition system are an additional hazard.
● Observe the following additional warnings
if work
on the fuel system or the electrical
system is necessary:
– Always disconnect the battery from the
on-board network.
– Do not smoke.
– Never work near naked flames.
– Always keep an approved fire extinguish-
er immediately available. CAUTION
When topping up fluids make sure the correct
fluid is p

ut into the correct filler opening, oth-
erwise this can cause serious malfunctions or
engine damage. For the sake of the environment
Inspect the ground underneath your vehicle
re gu

larly so that any leaks are detected at an
early stage. If you find spots of oil or other
fluids in the area where it was parked, have
your vehicle inspected at the workshop. Note
In right-hand drive vehicles* some brake flu-
id re ser

voirs are on the other side of the en-
gine compartment ››› Fig. 234. Opening the bonnet
Read the additional information carefully
› ›
›

 page 13
The bonnet is released from inside the vehi-
cle.
Check that the windscreen wiper arms are
not unfolded. Otherwise the paint may be
damaged.
The bonnet can only be unlocked when the
driver door is open. WARNING
Never open the bonnet if you see steam or
drips of

coolant being released from the en-
gine compartment. Failure to comply could
result in burns. Wait until no steam or coolant
can be seen before opening the bonnet. Closing the bonnet
–
Slightly lift the bonnet.
– Release the bonnet stay before pressing it
bac k

into its support.
– Carefully close the bonnet.
– Press the bonnet down until it locks into
plac

e.
– Make sure that the bonnet catches onto its
cla

sp. Do not press down too hard ››› .
WARNING
● For s af

ety reasons the bonnet must always
be completely closed when the vehicle is
moving. Therefore, after closing the bonnet,
always check that the locking element is
properly engaged. This is the case if the bon-
net is flush with the adjacent body panels.
● Should you notice that the bonnet is not
safely
secured when the vehicle is moving,
stop the vehicle immediately and close the
bonnet. Failure to follow this instruction
could result in an accident. 247
Technical data
Advice
Operation
Emergencies
Safety