alternator Seat Leon 5D 2017 Owner's manual

Driving
(2.5 miles), when fuel consumption will re-
t urn t
o a norm
al level.
Check tyre pressure
Always make sure the tyres are inflated to the
correct pressures ››› page 280 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. At speeds of 100-120
km/h (62-75 mph), this will save 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 he
ating*.
Power management This sy
stem helps to ensure reliable
starting The power management controls the distribu-
tion of el
ectric

al energy and thus helps to en-
sure that there is always enough power avail-
able to start the engine.
If a vehicle with a conventional electrical sys-
tem is left parked for a long time, the battery
will gradually lose its charge because certain
electrical devices, such as the electronic
gearbox lock continues to draw current even
when the ignition is off. In some cases there
may not be enough power available to start
the engine.
Your vehicle is equipped with an intelligent
power management system to control the
distribution of electrical energy. This signifi-
cantly improves 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 batt
er

y 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. »
201
Technical data
Advice
Operation
Emergencies
Safety

Operation
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 119. 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 management 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 s

tarting 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.
When the engine is running
Although the alternator 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 electric
al 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.
Engine management and emis-
sion contr
ol system
Introduction WARNING
● Bec au

se of the high temperatures which
can occur in the exhaust purification system
(catalytic converter or diesel particulate fil-
ter), do not park the vehicle where the ex-
haust can come into contact with flammable
materials under the car (e.g. on grass or at
the forest edge). Fire hazard! 202

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. 247. Opening the bonnet
Read the additional information carefully
› ›
›

 page 17
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. 271
Technical data
Advice
Operation
Emergencies
Safety