2012 Seat Leon 5D check engine light

210Checking and refilling levels
CAUTION
When changing or topping up service fluids, make absolutely certain that
you fill the fluids into the correct reservoirs. Using the wrong fluids could
cause serious malfunctions and engine damage!
For the sake of the environment
Inspect the ground underneath your vehicle regularly so that any leaks are
detected at an early stage. If you find spots of oil or other fluids, have your
vehicle inspected at the workshop.
Note
On right-hand drive vehicles* some of the containers/reservoirs mentioned
below are located on the other side of the engine compartment. 
Opening the bonnet
The bonnet is released from inside the vehicle.
Fig. 107 Release lever in driver footwell and cam below the bonnet 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.
–
Pull the lever under the dash panel in the direction of the arrow
1
⇒ Fig. 107.
– Lift the bonnet slightly ⇒ 
.
– Press the release catch under the bonnet upwards ⇒ Fig. 107
2
. This will release the arrester hook under the bonnet.
– Open the bonnet.
WARNING
Never open the bonnet if you see steam or drips of coolant being re-
leased from the engine compartment. Failure to comply could result in
burns. Wait until no steam or coolant can be seen before opening the
bonnet.

Closing the bonnet
– Press the bonnet down until it locks into place.
– Make sure that the bonnet catches onto its clasp. Do not press
down too hard ⇒ 
. 

215
Checking and refilling levels
Cooling system Engine coolant specifications
The engine cooling system is supplied from the factory with a specially trea-
ted mixture of water and, at least, 40 % of the additive G 13 (TLVW 774 J).
The engine coolant additive is recognisable by its purple colour. This mix-
ture of water and additive gives the necessary frost protection down to
-25°C (-13 F) and protects the light alloy parts of the cooling system against
corrosion. It also prevents scaling and considerably raises the boiling point
of the coolant.
To protect the engine cooling system, the percentage of additive must al-
ways be at least 40 %, even in warm climates where anti-freeze protection is
not required.
If greater frost protection is required in very cold climates, the proportion of
additive can be increased. However, the percentage of additive should not
exceed 60 %, as this would reduce the frost protection and, in turn, de-
crease the cooling capacity.
When the coolant is topped up, use a mixture of distilled water and, at
least, 40 % of the G 13 or G 12 plus-plus (TL-VW 774 G) additive (both are
purple) to obtain an optimum anticorrosion protection ⇒ 
. The mixture of
G 13 with G 12 plus (TL-VW 774 F), G 12 (red) or G 11 (green-blue) engine
coolants will significantly reduce the anticorrosion protection and should,
therefore be avoided ⇒ 
.
WARNING
If there is not enough anti-freeze in the coolant system, the engine may
fail leading to serious damage.
● Please make sure that the percentage of additive is correct with re-
spect to the lowest expected ambient temperature in the zone in which
the vehicle is to be used.
● When the outside temperature is very low, the coolant could freeze
and the vehicle would be immobilised. In this case, the heating would
not work either and inadequately dressed passengers could die of cold.
CAUTION
The original additives should never be mixed with coolants which are not
approved by SEAT. Otherwise, you run the risk of causing severe damage to
the engine and the engine cooling system.
● If the fluid in the expansion tank is not purple but is, for example,
brown, this indicates that the G 13 additive has been mixed with an inade-
quate coolant. The coolant must be changed as soon as possible if this is
the case! This could result in serious faults and engine damage.
For the sake of the environment
Coolants and additives can contaminate the environment. If any fluids are
spilled, they should be collected and correctly disposed of, with respect to
the environment. 
Safety FirstOperating instructionsPractical TipsTechnical specifications

216Checking and refilling levels
Topping up coolant
Top up coolant when the level is below the MIN (minimum)
mark.
Fig. 110 Engine com-
partment: Coolant expan-
sion tank cap
Checking coolant level
– Park the vehicle in a horizontal position.
– Switch the ignition off
– Read off the coolant level on coolant expansion tank. When the
engine is cold, the coolant level should be between the marks.
When the engine is hot, it may be slightly above the upper
mark.
Topping up coolant
– Wait for the engine to cool down.
– Cover the coolant expansion tank cap with a cloth and carefully
unscrew it to the left ⇒ 
. –
Top up the coolant only if there is still coolant in the expansion
tank, otherwise you could damage the engine. If there is no
coolant in the expansion tank, do not continue driving. You
should obtain professional assistance ⇒ 
.
– If there is still some coolant in the expansion tank, top up to the
upper mark.
– Top up with coolant to the upper mark until the level becomes
stable.
– Screw the cap back on correctly.
Any loss of coolant fluid normally indicates a leak in the cooling system.
Take the vehicle straight to a specialised workshop to have the cooling sys-
tem examined. If there are no leaks in the engine cooling system, a loss of
coolant can only occur if the coolant boils and is forced out of the system as
a result of overheating.
WARNING
● The cooling system is under pressure. Do not unscrew the cap on the
coolant expansion tank when the engine is hot: risk of burns!
● The antifreeze and coolant fluid can be a health hazard. Therefore,
the antifreeze should be stored in the original container in a safe place
out of reach of children. Failure to comply could result in poisoning.
● 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.
CAUTION
Do not top up the expansion tank with coolant fluid if it is empty! Air could
enter the cooling system. In this case, stop driving. Seek specialist assis-
tance. Otherwise, there is a risk of engine damage. 

217
Checking and refilling levels
Brake fluid
Fig. 111 Engine com-
partment: brake fluid res-
ervoir, lid
Checking the brake fluid level
The brake fluid level must be between the MIN and MAX markings.
However, if the brake fluid level goes down noticeably in a short time, or
drops below the MIN mark, there may be a leak in the brake system. Seek
specialist assistance. A warning light on the instrument panel display moni-
tors the brake fluid level ⇒ page 69.
In right-hand drive vehicles the brake fluid reservoir is on the other side of
the engine compartment.
Changing brake fluid
The regular intervals at which the brake fluid should be replaced are listed
in the Service Plan. We recommend you have the brake fluid replaced at a
SEAT Official Service, during an Inspection Service.
WARNING
● Brake fluid should be stored in the closed original container in a safe
place out of reach of children. Risk of poisoning!
● If the brake fluid is left in the system for too long and the brakes are
subjected to heavy use, vapour bubbles may form in the brake system.
This would seriously affect the efficiency of the brakes and the safety of
the vehicle. This may cause an accident.
CAUTION
Brake fluid should not come into contact with the vehicle paintwork, as it is
abrasive. 
Battery General information
The battery is located in the engine compartment and is almost mainte-
nance-free. It is checked as part of the Inspection Service. Nevertheless,
check the terminals are clean and have the correct tightening torque, espe-
cially in summer and winter.
Disconnecting the battery
The battery should only be disconnected in exceptional cases. When the
battery is disconnected, some of the vehicles functions are "lost" ( ⇒ table
on page 218). These functions will require resetting after the battery is re-
connected.
Deactivate the anti-theft alarm* before you disconnect the battery Other-
wise the alarm will be triggered. 
Safety FirstOperating instructionsPractical TipsTechnical specifications

218Checking and refilling levels
FunctionReprogrammingOne-touch function of the electric
windows⇒ page 101, One-touch opening and
closing*
Remote control keyIf the vehicle does not respond to the
key, they should be synchronised
⇒ page 90
Digital clock⇒ page 63
ESC warning lampAfter driving for a few metres, the
warning lamp goes out again.
If the vehicle is not used for long periods
The vehicle has a system for monitoring the current consumption when the
engine is left unused for long periods of time ⇒ page 187. Some functions,
such as the interior lights, or the remote door opening, may be temporarily
disabled to prevent the battery from running flat. These functions will come
back on as soon as the ignition is switched on and the engine started.
Winter conditions
During the winter, the starting power may be reduced, and if necessary, the
battery should be charged ⇒ 
in Important safety warnings for handling a
vehicle battery on page 218 
Important safety warnings for handling a vehicle battery
All work on batteries requires specialist knowledge. Please refer to a SEAT
Official Service or a workshop specialising in batteries: risk of burns or ex-
ploding battery!
The battery must not be opened. Never try to change the fluid level of the
battery. Explosive gas is released from the battery that could cause an ex-
plosion.
Wear eye protection.
Battery acid is very corrosive and caustic. Wear protective gloves
and eye protection. In the event of electrolyte splashes, rinse off
with plenty of water.
Fires, sparks, open flames and smoking are prohibited.
The battery should only be charged in a well-ventilated zone. Risk
of explosion!
Keep children away from acid and batteries!
WARNING
● When repairing or working on the electrical system, proceed as fol-
lows:
● 1. Remove the key from the ignition. The negative cable on the bat-
tery must be disconnected.
● 2. When the repair is finished, reconnect the negative pole of the bat-
tery.
● Switch off all electrical consumers before reconnecting the battery.
Reconnect first the positive cable and then the negative cable. Never re-
verse the polarity of the connections. This could cause an electrical fire.
● Ensure that the vent hose is always connected to the battery.
● Never use damaged batteries. This could cause an explosion! Replace
a damaged battery immediately.
CAUTION
● Never disconnect the battery if the ignition is switched on or if the en-
gine is running. This could damage the electrical system or electronic com-
ponents. 

220Checking and refilling levels
● Before starting any work on the battery, always observe the warnings lis-
ted under ⇒  page 218, Important safety warnings for handling a vehicle
battery.
● Do not forget to replace the battery coverings, where applicable. This
helps to protect against excess temperatures. This in turn extends the vehi-
cle service life.
For the sake of the environment
 Batteries contain toxic substances including sulphuric acid and lead. They
must be disposed of appropriately and must not be disposed of with ordi-
nary household waste. Make sure disconnected batteries cannot tip over.
Sulphuric acid could be spilt! 
Windscreen washer reservoir and wiper
blades
Windscreen washer
Fig. 112 Engine com-
partment: Windscreen
washer reservoir top The windscreen washer reservoir  contains the cleaning fluid for the wind-
screen, the rear window and the headlight washer system* ⇒ Fig. 112. Res-
ervoir capacity: ⇒ page 276.
To prevent the nozzles from becoming blocked with chalk deposits, fill res-
ervoir with water with a low calcium content (distilled water). Always add
washer fluid to the water (with anti-freeze additive in winter).
CAUTION
● Never put radiator anti-freeze or other additives into the windscreen
washer fluid.
● Never use washer fluid which contains paint thinners or solvents as it
can damage the paintwork. 

250Fuses and bulbs
–Unlock the fuse cover ⇒ Fig. 132.
– Remove the clips from the fuse cover.
– Use the plastic clip to pull out the fuse and replace the blown
fuse with a fuse of the same rating.
The individual electrical circuits are protected by fuses. Fuses are located
under a cover below the steering wheel on the left side of the engine com-
partment.
WARNING
Do not repair fuses, and never replace a blown fuse with a higher amper-
age fuse. The electrical system could be damaged, with risk of fire.
CAUTION
● Multiple fuse values on the same line (for example, 5/10/20) in the fol-
lowing tables indicate equipment-related differences. Replace the blown
fuse with a fuse of the same amperage.
● If a newly replaced fuse blows again after a short time, the electrical sys-
tem must be checked by a specialised workshop as soon as possible.
Note
● Positions are not occupied by a fuse do not appear in the following ta-
bles.
● Some of the equipment listed in the tables below pertain only to certain
versions of the model or are an optional extra. Fuses in the vehicle interior
No.Electrical consumerAmpsF2Vacant-F4Alarm10F5Gateway5F6Anti-theft alarm system5
F7Air conditioner/heating control panel, selector
lever (automatic gearbox), relay coil, rear win-
dow heating, additional heating10
F8Diagnosis, handbrake switch, light switch, re-
verse light, interior lighting10
F9Vacant-F10Radio display10F11Vacant-F12Radio20F13Vacant-F14Air conditioner fan40F15Vacant-F16Vacant-F17Instrument panel5F18Vacant-F19Vacant-F20Vacant-F23Right lights40F24Sunroof30F25Left door30F26Heated seats30F27Vacant-F28Vacant-


253
Fuses and bulbs
LED rear lightTypeReverse lightsP21W LLThe remaining functions work with LEDs
WARNING
● Take particular care when working on components in the engine com-
partment if the engine is warm. Risk of burns.
● Bulbs are highly sensitive to pressure. The glass can break when you
touch the bulb, causing injury.
● When changing bulbs, please take care not to injure yourself on sharp
edges, in particular on the headlight housing.
CAUTION
● Remove the ignition key before working on the electric system. Other-
wise, a short circuit could occur.
● Switch off the lights or parking lights before you change a bulb.
● Take good care to avoid damaging any components.
For the sake of the environment
Please ask your specialist retailer how to dispose of used bulbs in the prop-
er manner.
Note
● Please check at regular intervals that all lighting (especially the exterior
lighting) on your vehicle is functioning properly. This is not only in the inter-
est of your own safety, but also that of all other road users.
● Before changing a bulb, make sure you have the correct new bulb.
● Do not touch the glass part of the bulb with your bare hands, use a cloth
or paper towel instead. Otherwise, the fingerprints left on the glass will va-
porise as a result of the heat generated by the bulb, they will be deposited
on the reflector and will impair its surface. 
Safety FirstOperating instructionsPractical TipsTechnical specifications