2012 Seat Leon 5D alternator

188Intelligent technology
Depending on the power level of the battery, the individual electrical com-
ponents are switched off one after the other to prevent the battery from los-
ing too much charge and to ensure that the engine can be started reliably.
Dynamic power management
While the vehicle is moving, this function distributes the available power to
the various electrical components and systems according to their require-
ments. The power management ensures that on-board systems do not con-
sume more electrical power than the alternator can supply, and thus main-
tains the maximum possible battery power level.
Note
● The power management system is not able to overcome the given physi-
cal limits. Please remember that the power and useful life of the battery are
limited.
● When there is a risk that the vehicle will not start, the alternator power
failure or low battery charge level warning lamp will be shown 
⇒ page 69. 
Note carefully
Starting ability has first priority. Short trips, city traffic and low temperatures all place a heavy load on the
battery. In these conditions a large amount of power is consumed, but only
a small amount is supplied. The situation is also critical if electrical equip-
ment is in use when the engine is not running. In this case power is con-
sumed 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 management will gradually shut off the on-board systems one by
one, or reduce the amount of current they are using. This limits the amount
of power consumed and helps to ensure reliable starting even after a long
period. Some convenience functions, such as remote vehicle opening, may
not be available under certain circumstances. These functions will be re-
stored when you switch on the ignition and start the engine.
With the engine switched off
For example, if you listen to the sound system 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 bat-
tery can recharge.
When the engine is running
Although the alternator generates electrical power, the battery can still be-
come discharged while the vehicle is being driven. This can occur when a
lot of power is being consumed but only a small amount supplied, especial-
ly if the battery is not fully charged initially.
To restore the necessary energy balance, the system will then temporarily
shut off the electrical components that are using a lot of power, or reduce
the current they are consuming. Heating systems in particular use a large
amount of electrical power. If you notice, for instance, that the seat heating*
or the heated rear window 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 electrical power is available.
You may also notice that the engine runs at a slightly faster idling speed.
This is quite normal, and no cause for concern. The increased idling speed
allows the alternator to meet the greater power requirement and charge the
battery at the same time.


192Driving and the environment
Reduce idling time
In vehicles with the Start-Stop system idling is automatically reduced. In ve-
hicles without the Start-Stop system it is worth switching off the engine, for
example, at level crossings and at traffic lights that remain red for long peri-
ods of time. When an engine has reached operating temperature, and de-
pending on the cylinder capacity, keeping it off after about 5 seconds al-
ready saves more than the amount of fuel necessary for restarting.
The engine takes a long time to warm up when it is idling. Mechanical wear
and pollutant emissions are also especially high during this initial warm-up
phase. It is therefore best to drive off immediately after starting the engine.
Avoid running the engine at high speed.
Regular maintenance
Regular servicing helps in saving fuel even before the engine is started. A
well-serviced engine gives you the benefit of improved fuel efficiency as
well as maximum reliability and an enhanced resale value. A badly serviced
engine can consume up to 10% more fuel than necessary.
Avoid short journeys
The engine and catalytic converter need to reach their optimal operating
temperature in order to minimise fuel consumption and emissions.
A cold engine consumes a disproportionate amount of fuel. The engine only
reaches its working temperature after about four kilometres (2.5 miles),
when fuel consumption will return to a normal level.
Check tyre pressure
Always make sure the tyres are inflated to the correct pressures
⇒ page 223 to save fuel. If the pressure is below half bar, fuel consumption
may increase by 5%. Due to the greater rolling resistance, under-inflation
also increases 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 increase the fuel consumption, it is
advisable to always check the luggage compartment to make sure that no
unnecessary loads are being transported.
Since the luggage rack increases the aerodynamic 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), approximately 12% of fuel.
Save electrical energy
The engine drives the alternator, thereby generating electricity. This implies
that any increase in power consumption also increases fuel consumption!
For this reason, switch off any unneeded consumption of electricity. Electri-
cal equipment which uses a lot of electricity includes the blower (at a high
setting), the rear window heating and the seat heating*. 
Environmental friendliness
Environmental protection is a top priority in the design, choice of materials
and production of your new SEAT.
Design measures for economical recycling
● Joints and connections designed for easy dismantling
● Modular construction to facilitate dismantling
● Increased use of single-grade materials
● Plastic parts and elastomers are rated in accordance with ISO 1043, ISO
11469 and ISO 1629
Choice of materials
● Nearly all materials used can be recycled
● Use of suitable plastics within the same system/set
● Recycled materials used in manufacture 

209
Checking and refilling levels
Note
Diesel vehicles are fitted with a protective device that prevents the insertion
of the wrong fuel hose 1)
. It is only possible to refuel with Diesel nozzles.
● If the pump nozzle is worn, damaged, or if it is very small, it is possible
that it will not be able to open the protective device. Before trying to insert
the pump nozzle by turning it, try a different pump or request specialist
help.
● If you fill the tank from a reserve fuel canister, the protective device will
not open. One way to resolve this is to pour the fuel in very slowly. 
Bonnet
Working on components in the engine compartment
Extra caution is necessary when working on components in
the engine compartment. Always be aware of the danger of injury and scalding as well as the risk of
accident or even fire when working in the engine compartment (e.g. when
checking and refilling fluids). Always observe the warnings listed below
and follow all general safety precautions. The engine compartment of the
vehicle is a potentially hazardous area ⇒ 
.
WARNING
● Switch the ignition off.
● Remove the ignition key.
WARNING (Continued)
● Apply the handbrake.
● If the vehicle has a manual gearbox, place the lever in neutral; if it
has an automatic gearbox, place the selector lever in position P.
● Wait for the engine to cool down.
● Keep children away from the engine compartment.
● Never spill liquids used for vehicle operation on the engine compart-
ment, as these may catch fire (e.g. the antifreeze in coolant).
● Take care not to cause short circuits in the electrical system, especial-
ly when working on the battery.
● If working inside the engine compartment, remember that, even when
the ignition is switched off, the radiator fan may start up automatically,
and therefore there is a risk of injury.
● Do not unscrew the cap on the coolant expansion tank when the en-
gine is hot. The cooling system is under pressure.
● Protect face, hands and arms by covering the cap with a large, thick
rag to protect against escaping coolant and steam.
● If it is necessary to work in the engine compartment while the engine
is running, the rotating components (for example, poly-V belt, alternator,
radiator fan) and the high voltage ignition system are an additional haz-
ard.
● 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 extinguisher immediately available. 
1)
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