Get Practical tips -> Checking and refilling levels Guide for Cupra Leon 4 Door First Generation (2020-2026)

Checking and refilling levels

●

After a few seconds the fuel tank flap will un-

lock and remain unlocked for a few minutes.

If you have not refuelled after this time, you

must press the  button again before refuel-

ling.

Hybrid vehicles: Use the  button on the

driver’s door to release the tank flap.

Practical tips

●

Open the fuel tank flap by pressing on the

retainer zone.

Checking and refilling

levels

●

Unscrew the cap by turning it to the left.

Avoid touching the fuel tank flap lock button

Place it in the space on the hinge of the

Fig. 213 (arrow). The system will interpret

›››

open flap Fig. 213 .

›››

that you have finished and cannot continue

refuelling. Press the  button on the driver’s

door again to continue.

Refuelling

●

Start refuelling. The tank is full as soon as

the pump’s automatic nozzle cuts off the

fuel supply. Do not try to put in more fuel af-

ter the nozzle cuts out, as this will fill the ex-

pansion chamber in the fuel tank.

Purging the fuel tank

3 Valid for: hybrid vehicles.

Refuelling

●

Unscrew the cap by turning it to the right

as far as it will go.

●

Close the lid.

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 313.

›››

The capacity of your vehicle's fuel tank is giv-

en in page 360 .

›››

Fig. 212 Driver's door: tank flap release.

Hybrid vehicles

Fig. 213 Fuel tank flap with tank cap at-

tached.

Before refuelling the fuel system must be

depressurised

page 312. To do this, press the  button on

in Refuelling on

›››

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.

The fuel tank flap is on the rear right of the

vehicle.

the driver’s door.

An audible sound will be played and a warn-

ing will be displayed on the instrument clus-

ter display.

The flap that covers the tank cap is unlocked

and locked automatically using the central

locking.

»

311

Practical tips

WARNING

tact with the canister during filling. This

helps prevent an electrostatic charge

building up.

essary, request assistance from specialised

personnel.

Fuel is highly flammable and can cause se-

rious burns and other injuries.

–

Never spill fuel in the vehicle or in the

luggage compartment. Fuel vapour is

explosive. Risk of fatal accident!

Note

●

When refuelling, turn off the engine and

turn off the ignition for safety reasons.

Diesel vehicles are fitted with a protective

device that prevents the insertion of the

wrong fuel hose¹⁾. It is only possible to re-

fuel with Diesel nozzles.

●

The fuel system of PHEV models is pres-

surized to prevent petrol vapours from es-

caping into the atmosphere.

CAUTION

●

If any fuel is spilt onto the vehicle, it

If the pump nozzle is worn, damaged, or if

Do not smoke when filling the fuel tank or

should be removed immediately. It could

otherwise damage the paintwork.

it is very small, it is possible that it will not

be able to open the protective device. Be-

fore trying to insert the pump nozzle by

turning it, try a different pump or request

specialist help.

a canister. Naked flames are forbidden in

the vicinity due to the risk of explosion.

●

Never run the tank completely dry. The

Observe legislation governing the use,

catalytic converter can be damaged.

storage and carrying of a spare fuel canister

in the vehicle.

●

When filling the fuel tank after having run

●

If you fill the tank from a reserve fuel can-

●

it completely dry on a vehicle with a diesel

engine, the ignition must be switched on

for at least 30 seconds before starting the

engine. When you then start the engine it

may take longer than normal (up to one mi-

nute) to start firing.

For safety reasons we do not recommend

ister, the protective device will not open.

One way to resolve this is to pour the fuel in

very slowly.

carrying a spare fuel canister in the vehicle.

In an accident the canister could be dam-

aged and could leak.

●

If, in exceptional circumstances, you have

to carry a spare fuel canister, please ob-

serve the following points:

For the sake of the environment

–

Never fill fuel into the spare fuel canis-

ter if it is inside or on top of the vehicle.

This could cause an explosion. Always

place the canister on the ground to fill

it.

Do not overfill the fuel tank, it may cause

the fuel to overflow if it becomes warm.

Note

–

Insert the filling nozzle as far as possi-

ble into the spare fuel canister.

There is no emergency mechanism for the

manual release of the fuel tank flap. If nec-

If the spare fuel canister is made of

metal, the filling nozzle must be in con-

1)

Depending on country

312

Checking and refilling levels

2

Diesel according to EN590 standard. The

number indicates the maximum per-

centage of Biodiesel in the fuel. “B7”

means a maximum of 7% Biodiesel.

91 octane petrol (87 AKI) (with a slight power

loss) may be used.

Fuel types

Identification of fuels¹⁾

Super unleaded petrol, 95 octanes at least

3

Synthetic diesel according to EN15940

standard.

You should use super 95 octane petrol (91

AKI) at least.

4

Natural gas: “CNG” means Compressed

Natural Gas.

If super is not available, if necessary, use

normal 91 octane petrol (87 AKI). In this case

only use moderate engine speeds and a light

throttle. Refuel with super as soon as possi-

ble.

Type of petrol

The correct grade of petrol is listed inside

the fuel tank flap.

Unleaded super plus 98 octane petrol or

super 95 octane petrol at least

The vehicle is equipped with a catalytic con-

verter and must only be run on unleaded

petrol. The petrol must comply with the

standard EN 228 and be sulphur-free. Fuels

with a 10% ethanol ratio can be refuelled

(E10)²⁾. The types of petrol are differentiated

by using the octane numbers (RON) or via

the anti-knock index (AKI).

We recommend refuelling with super plus 98

octane petrol (93 AKI). If not available: super

95 octane petrol (91 AKI) (with a slight power

loss).

Fig. 214 Identification of fuels according

to European Union (EU) Directive

2014/94/

If super is not available, if necessary, use

normal 91 octane petrol (87 AKI). In this case

only use moderate engine speeds and a light

throttle. Refuel with super as soon as possi-

ble.

Fuels are identified by different symbols on

the pump and on your vehicle's tank flap.

The identification serves to prevent confu-

sion when choosing the fuel.

»

Super unleaded petrol 95 octane petrol or

normal 91 octane petrol at least

1

Petrol with ethanol (“E” stands for Etha-

nol). The number indicates the percent-

age of ethanol in the petrol. “E5” means,

for example, an ethanol ratio of 5% max.

We recommend refuelling with super 95 oc-

tane petrol (91 AKI). If not available, normal

1)

Depending on country

2)

Follow the regulations of the country you are

driving in.

313

Practical tips

CAUTION

It lights up

Engine management and

emissions control system



●

Fuels high percentage of ethanol, e.g.

Fault in the petrol engine management.

Have the engine checked as soon as possible by a spe-

cialised workshop.

E30 - E100 button must not be used. The

fuel system would be damaged.

Introduction

●

A single refuelling with leaded fuel or

When the ignition is switched on, the  (Electronic

Power Control) lights up and should go off once the

engine has started.

other metal additives entails a permanent

deterioration of the effectiveness of the

catalytic converter.

WARNING

●

Due to the high temperatures reached by

the exhaust gas scrubbing system, you

should not park your vehicle near a surface

that can catch fire easily. Fire hazard!

●

Only use fuel additives that have been

Note

approved by SEAT. The products that con-

tain substances to increase the octane rat-

ing or decrease knocking may contain met-

al additives that damage the engine and

catalytic converter. This type of products

must not be used.

While the indicator lamps ,  or  are

on, there might be faults in the engine, fuel

consumption may go up and the engine

might lose power.

●

Do not apply wax underneath the vehicle

around the area of the exhaust system: Fire

hazard!

●

Do not use fuels shown in the pump as

Catalytic converter

containing metals. LRP (lead replacement

petrol) fuels contain high concentrations of

metal additives. Risk of engine damage!

Control lamps

To maintain the useful life of the catalytic

converter

It lights up



●

High engine speed and full throttle can

damage the engine when using petrol with

an octane rating lower than the correct

grade for the engine.

●

Only use unleaded petrol with petrol en-

gines.

Fault in the emission control system.

Reduce speed and drive carefully to the nearest speci-

alised workshop to have the engine checked.

●

Never run the fuel tank dry.

When changing or adding engine oil, do

Flashes

Note



not exceed the necessary amount

›››

●

Fuel with an octane rating higher than

Combustion failures that can damage the catalytic

converter.

Reduce speed and drive carefully to the nearest speci-

alised workshop to have the engine checked.

page 321, Topping up the engine oil.

the one required by the engine can be

used.

Never tow the vehicle to start it, use jump

leads if necessary page 54 .

›››

●

In countries in which there is no sulphur-

free fuel, it is also allowed to use low sul-

phur content fuel.

If you should notice misfiring, uneven run-

ning or loss of power when the car is moving,

have the vehicle inspected by a specialised

workshop. In general, the emissions warning

It lights up



Particulate filter blocked page 315 .

›››

314

Checking and refilling levels

●

lamp  will light up when any of these symp-

toms occur. If this happens, any unburnt fuel

can enter the exhaust system and escape in-

to the atmosphere. The catalytic converter

can also be damaged by overheating.

vehicle is moving. See Manual. The

particulate filter needs cleaning (regenera-

tion).

Consider the legal speed limits as well as

the recommended gears.

●

End the regeneration journey once the

control warning lamp has gone out.

Regeneration of the particulate filter (only

for 2.0l TSI engines)

If the warning lamp stays on after 30 minutes

of running in regeneration mode, have a

specialised workshop repair the fault.

CAUTION

Requirements for the regeneration journey:

Never run the fuel tank completely dry be-

cause an irregular fuel supply can cause ig-

nition faults. This allows unburnt fuel to en-

ter the exhaust system, which could cause

overheating and damage the catalytic con-

verter.

the engine is at operating temperature.

WARNING

●

Drive at a speed of at least 80 km/h

›››

Always adjust your speed to suit the weath-

er conditions, roads, braking distance and

traffic if the particulate filter is in its regen-

eration phase. Route recommendations

should never make you disregard each

country's specific traffic regulations.

Completely remove your foot from the ac-

celerator pedal for a few seconds to let the

vehicle roll with the gear engaged.

●

Consider the legal speed limits as well as

the recommended gears.

For the sake of the environment

Even when the emission control system is

working perfectly, there may be a smell of

sulphur from the gases on occasions. This

depends on the sulphur content of the fuel

used. This can quite often be avoided by

changing to another brand of fuel.

●

Repeat this procedure (accelerate and let

roll) until the control lamp turns off.

CAUTION

This procedure involves an autonomous par-

ticulate filter cleaning process and may take

some time.

●

When the exhaust system detects that

the particulate filter is close to saturation,

the self-cleaning function of this system

recommends optimal driving for this func-

tion.

If the warning lamp does not turn off, go im-

mediately to a specialised workshop to repair

the fault.

●

Due to the high temperatures caused by

Particulate filter

the regeneration of the particulate filter, it

is possible that the radiator fan will activate

after stopping the engine, even it its oper-

ating temperature has not been reached.

The particulate filter eliminates most of the

soot from the exhaust gas system. Under

normal driving conditions the filter cleans it-

self. If the filter does not clean itself (e.g. if

short journeys are made continuously), it be-

comes blocked with soot and the following

indication is displayed to the driver:  Par-

ticulate filter: cleaned while the

Regeneration of the petrol (except the TSI

2.0l engine) particulate filter

Requirements for the regeneration journey:

●

Noise, smells and high idle speeds can

the engine is at operating temperature.

occur during regeneration.

●

Always use the correct engine oil and the

●

Drive at a speed of between 50-120 km/h

(31-75 mph). This increases the temperature

and burns the soot in the filter

»

correct fuel to make sure the useful life of

.

›››

315

Practical tips

the particulate filter is not affected. Also

avoid making short trips all the time.

or coolant can be seen before opening the

bonnet.

securing the vehicle and there is a risk of

injury.

●

Keep children away from the engine com-

If any work has to be performed when the

partment.

engine is started or with the engine run-

ning, there is an additional, potentially fa-

tal, safety risk from the rotating parts, such

as the drive belts, alternator, radiator fan,

etc., and from the high-voltage ignition sys-

tem. You should also observe the following:

●

Never spill liquids used for vehicle opera-

Engine compartment

tion on the engine compartment, as these

may catch fire (e.g. the antifreeze in cool-

ant).

Working in the engine compart-

ment

●

Avoid causing short-circuits in the elec-

–

Never touch the electrical wiring of the

ignition system.

trical system, particularly at the points

where the jump leads are attached

Always be aware of the danger of injury and

scalding as well as the risk of accident or fire

when working in the engine compartment

(e.g. when checking and refilling fluids).

–

page 54. The battery could explode.

Ensure that jewellery, loose clothing

and long hair do not get trapped in ro-

tating engine parts. Danger of death.

Before starting any work remove jewel-

lery, tie back and cover hair, and wear

tight-fitting clothes.

›››

●

If working inside the engine compart-

ment, remember that, even when the igni-

tion is switched off, the radiator fan may

start up automatically, and therefore there

is a risk of injury.

Always observe the warnings listed below

and follow all general safety precautions.

The vehicle's engine compartment is a po-

–

Never accelerate with a gear engaged

without taking the necessary precau-

tions. The vehicle could move, even if

the handbrake is applied. Danger of

death.

●

Never cover the engine with additional

tentially hazardous area

.

›››

insulating materials such as a blanket. Risk

of fire!

WARNING

●

Do not unscrew the cap on the coolant

When work is done in the engine compart-

ment, injuries, burns, accidents and even

fires can occur.

expansion tank when the engine is hot. The

cooling system is under pressure.

●

Observe the following additional warn-

ings if work on the fuel system or the elec-

trical system is necessary:

●

Protect face, hands and arms by covering

●

Turn off the engine, disconnect the igni-

the cap with a large, thick rag to protect

against escaping coolant and steam.

–

Always disconnect the battery from the

on-board network.

tion e and apply the electronic parking

brake. Activate the automatic gearbox

parking lock (button P). Wait for the engine

to cool down.

●

Always make sure you have not left any

–

Do not smoke.

objects, such as cleaning cloths or tools, in

the engine compartment.

Never work near naked flames.

●

Never open the bonnet if you see steam

●

If you have to work underneath the vehi-

Always keep an approved fire extin-

guisher immediately available.

or drips of coolant being released from the

engine compartment. Wait until no steam

cle, you must use suitable stands addition-

ally to support the vehicle, there is a risk of

accident!. A hydraulic jack is insufficient for

316

Checking and refilling levels

●

Open the door and pull the lever under the

Opening and closing the bonnet

For the sake of the environment

Inspect the ground underneath your ve-

1

dashboard Fig. 215

.

›››

●

To lift the bonnet, press towards the left on

hicle regularly so that any leaks are detec-

ted 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.

the lever located under the bonnet, in the

centre Fig. 216

released.

2

. The arrester hooks are

›››

●

The bonnet can be opened. Release the

●

Service fluids leaks are harmful to the en-

bonnet stay and secure it in the fixture de-

signed for this in the bonnet.

vironment. For this reason you should make

regular checks on the ground underneath

your vehicle. If you find spots of oil or other

fluids, have your vehicle inspected in a spe-

cialised workshop.

Closing the bonnet

●

Slightly lift the bonnet.

Fig. 215 Release lever in the driver's foot-

well area.

Release the bonnet stay and replace it in its

support.

Note

●

At a height of approximately 20 cm let it fall

In right-hand drive vehicles some brake flu-

id reservoirs are on the other side of the

so it locks.

engine compartment Fig. 217 .

›››

If the bonnet does not close, do not press

downwards. Open it again and let it fall as

mentioned above.

WARNING

Make sure that the bonnet is properly

closed. If it opens when driving, it can cause

an accident.

Fig. 216 Lever under the bonnet.

Opening the bonnet

CAUTION

The bonnet is released from inside the vehi-

cle.

To avoid damage to the bonnet and to the

windscreen wiper arms, only open it when

the windscreen wipers are in place against

the windscreen.

Before opening the bonnet, make sure that

the windscreen wiper arms are in place

against the windscreen.

317

Practical tips

Checking levels

Fig. 217 Diagram for the location of the vari-

ous elements.

From time to time, the levels of the different

fluids in the vehicle must be checked. Never

fill with incorrect fluids, otherwise serious

damage to the engine may be caused.

Note

The layout of parts may vary depending on

the engine.

1

Coolant expansion tank page 322

›››

2

Brake fluid reservoir page 324

›››

3

Engine oil filler cap page 321

›››

4

Engine oil level dipstick page 320

›››

5

Battery page 326

›››

6

Windscreen washer reservoir

page 325

›››

318

Checking and refilling levels

The engine comes with a special, multi-

grade oil that can be used all year round.

a specialised CUPRA Service or SEAT Official

Service.

Engine oil

Because the use of high-quality oil is essen-

tial for the correct operation of the engine

and its long useful life, when topping up or

changing oil, use only those oils that comply

with VW standards.

CUPRA recommends the use of engine oils

approved according to the appropriate VW

standard. Use of engine oils that do not meet

these quality requirements can cause engine

damage.

General notes

CUPRA recommends the use of Original

SEAT Spare Part engine oils.

For vehicles with an engine oil label

If the engine oil has to be topped up, use one

of the oils shown on the label Fig. 218 .

The label with the prescribed standard is lo-

›››

Engine oil additives

No type of additive should be mixed with the

engine oil. The deterioration caused by

these additives is not covered by the warran-

ty.

cated at the front of the engine compart-

1

ment Fig. 219

. If you use the recom-

›››

Fig. 218 In the engine compartment: en-

gine oil label

mended engine oil, you can top up the oil as

often as necessary.

CAUTION

For vehicles without an engine oil label

Take the following into account if you have

refilled with an engine oil different to those

specified in the aforementioned standards,

or by your SEAT technical service centre:

Contact a specialised workshop or SEAT offi-

cial service for information about the corre-

sponding standard.

●

There is no way of completely avoiding

If the engine oil level is too low

the danger of causing damage to the en-

gine and particulate filter.

If the recommended engine oil is not availa-

ble, in the event of an emergency you can

change the oil once with a maximum of 0.5 L

of the next oil until the next oil change:

●

You can continue driving with the vehicle

Fig. 219 In the engine compartment: area

where the engine oil label is located

if the refill was no more than 0.5 l of engine

oil. Go to a specialised workshop as soon as

possible and request an oil change. Other-

wise, there is a danger of engine damage.

Key to the Fig. 218 :

›››

–

Petrol engines: VW 504 00, ACEA C3 or

A

Information about the engine oil stand-

API SN standard.

●

If you have topped up more than 0.5 l of

ard.

engine oil, drive with the engine at low load

levels and within the medium RPM range as

CUPRA recommends changing the oil at a

specialised workshop. CUPRA recommends

B

Information about engine oil viscosity.

»

319

Practical tips

Warning lamp

Checking the engine oil level

a maximum. Do not drive at more than 80

km/h and do not travel more than 300 km

(approximately). Go to a specialised work-

shop as soon as possible and request an oil

change. Otherwise, there is a danger of en-

gine damage.

It lights up red

Do not carry on driving!





Engine oil pressure too low.

Switch off the engine. Check the engine oil level.

●

You are responsible for the risk of possi-

ble damage to the vehicle (engine, exhaust

system). If in doubt, do not start the engine

and request assistance from the technical

service centre.

If this warning lamp

nied by three audible warnings, switch off the engine

and check the oil level. If necessary, add more oil



starts to flash, and is accompa-

page 321.

›››

●

Do not start the engine if you have top-

If the warning lamp



flashes although the oil level is

correct, stop driving. Do not even run the engine at

idle speed! Obtain technical assistance.

ped up with a fluid other than engine oil.

Request assistance from the technical serv-

ice centre. Danger of engine damage!

Fig. 220 Engine oil dipstick.

The engine oil dipstick indicates the level of

the oil.

It lights up yellow



Note

Check the engine oil level as soon as possible.

Checking oil level

Replace oil as soon as you have the opportunity to do

so page 321 .

›››

Before a long trip, we recommend finding

an engine oil that conforms to the corre-

sponding VW specifications and recom-

mend keeping it in the vehicle. This way,

the correct engine oil will always be availa-

ble for a top-up if needed.

–

Park the vehicle in a horizontal position.

Briefly run the engine at idle speed until

the operating temperature is reached and

then stop.

It flashes yellow



Fault in the oil level sensor.

Have the check done by a specialised workshop. Until

then it is advisable to check the oil level every time you

refuel.

–

Wait for about two minutes.

Pull out the dipstick. Wipe the dipstick with

a clean cloth and insert it again, pushing it

in as far as it will go.

WARNING

Observe the safety warnings

in Con-

›››

–

Then pull it out once more and check the

trol and warning lamps on page 87.

oil level Fig. 220 . Top up with engine oil

›››

if necessary.

A

The oil must leave a mark between zones

C

A

and . It can never go above zone

.

320

Checking and refilling levels

Topping up the engine oil

●

A

Zone : do not add oil.

The position of the oil filler opening is shown

in the corresponding engine compartment

B

Zone : you can add oil but keep the level

illustration page 318 .

›››

in that zone.

Engine oil specification page 319 .

●

C

B

›››

Zone : add oil until zone

.

Depending on how you drive and the condi-

tions in which the vehicle is used, oil con-

sumption can be up to 0.5 l/1000 km. Oil

consumption is likely to be higher for the first

5,000 km. For this reason the engine oil level

must be checked at regular intervals, pref-

erably when filling the tank and before a

journey.

WARNING

Oil is highly inflammable! Ensure that no oil

comes into contact with hot engine com-

ponents when topping up.

CAUTION

Fig. 221 In the engine compartment: En-

gine oil filler cap.

If the oil level is above area Fig. 220

A

,

›››

do not start the engine. This could result in

damage to the engine and catalytic con-

verter. Contact a specialised workshop.

WARNING

Before opening the bonnet, read and ob-

Any work carried out in the engine com-

partment or on the engine must be carried

out cautiously.

serve the warnings

engine compartment on page 316.

in Working in the

›››

For the sake of the environment

The oil level must never be above zone

●

When working in the engine compart-

Topping up engine oil

ment, always observe the safety warnings

A

Fig. 220 . Otherwise oil can be drawn in

›››

●

Unscrew cap from engine oil filler opening

page 316.

›››

through the crankcase breather and leak

into the atmosphere via the exhaust sys-

tem.

Fig. 221.

›››

●

Carefully add oil in small quantities (no

more than 0.5 l).

CAUTION

A

If the oil level is above area , do not start

●

Note

To avoid adding too much oil, whenever

the engine. This could result in damage to

the engine and catalytic converter. Contact

a Technical Service.

you add a certain amount, wait about 2 mi-

nutes and recheck the oil level page 320 .

Before a long trip, we recommend finding

an engine oil that conforms to the corre-

sponding VW specifications and recom-

mend keeping it in the vehicle. This way,

the correct engine oil will always be availa-

ble for a top-up if needed.

›››

●

If necessary, add some more oil.

When the oil level reaches at least zone

B

Fig. 220 , unscrew the engine oil filler

›››

cap carefully

.

›››

321

Practical tips

increased, but only up to 60 %; otherwise

antifreeze protection will diminish and this

will worsen cooling.

Engine oil change

For the sake of the environment

We recommend that you change the en-

●

We recommend that you have the engine oil

changed by a Technical Service.

gine oil and the filter at a technical service

centre.

When the coolant is topped up, use a mix-

ture of distilled water and at least 40 % of

the additive G12evo for optimal protection

against corrosion. Mixing G12evo with G13

(TL-VW 774 J), G12 plus-plus (TL-VW 774 G),

G12 plus (TL-VW 774 F), G12 (red) or G11

(green blue) engine coolants decreases pro-

tection again corrosion and should be avoi-

ded.

●

Never pour oil down drains or into the

WARNING

ground.

Only change the engine oil yourself if you

have the specialist knowledge required!

●

Use a suitable container when draining

the used oil. It must be large enough to

hold all the engine oil.

●

Before opening the bonnet, read and ob-

serve the warnings page 316 .

›››

Wait for the engine to cool down. Hot oil

●

may cause burn injuries.

Cooling system

●

Wear eye protection to avoid injuries,

WARNING

such as acid burns, caused by splashes of

oil.

If there is not enough anti-freeze in the

coolant system, the engine may fail leading

to serious damage.

Coolant specifications

●

When removing the oil drain plug with

The engine cooling system is supplied from

the factory with a specially treated mixture of

water and at least 40 % of the additive

G12evo (TL-VW 774 J), purple. This mixture

gives the necessary frost protection down to

-25°C (-13°F) and protects the light alloy

parts of the engine cooling system against

corrosion. It also prevents scaling and con-

siderably raises the boiling point of the cool-

ant.

your fingers, keep your arm horizontal to

help prevent oil from running down your

arm.

●

Ensure that the percentage of additive is

correct for the lowest expected ambient

temperature in the zone in which the vehi-

cle is to be used.

●

Wash your skin thoroughly if it comes into

contact with engine oil.

●

When the outside temperature is very

●

Engine oil is poisonous! Used oil must be

low, the coolant could freeze and the vehi-

cle would be immobilised.

stored in a safe place out of the reach of

children.

CAUTION

To protect the cooling system, the percent-

age of additive must always be at least 40 %,

even in warm climates where anti-freeze

protection is not required.

The original additives should never be

mixed with coolants which are not ap-

proved by SEAT.

No additives should be used with engine oil.

This could result in engine damage. Any

damage caused by the use of such additives

would not be covered by the factory war-

ranty.

●

If the fluid in the expansion tank is not

purple but is, for example, brown, this indi-

cates that the G12evo additive has been

If for weather reasons further protection is

necessary, the proportion of additive may be

322

Checking and refilling levels

2

Coolant expansion tank for the high-

voltage cooling circuit. Do not continue

driving if there is a lack of fluid in the ex-

pansion tank. Do not top up coolant. Go

immediately to a specialised workshop.

mixed with an inadequate coolant. The

coolant must be changed as soon as possi-

ble if this is the case!

For the sake of the environment

Coolants and additives can contaminate

the environment. If any fluids are spilled,

they should be collected and correctly dis-

posed of, with respect to the environment.

Refilling coolant

Fig. 224 Engine compartment: coolant

expansion tank cap.

Coolant tank

The coolant tank is located in the engine

3 Valid for: hybrid vehicles.

compartment page 318 .

›››

Top up coolant when the level is below the

 (minimum) mark.

Checking coolant level

Fig. 223 In the engine compartment:

marking on coolant expansion tank.

–

Park the vehicle in a horizontal position.

Switch the ignition off.

Read off the coolant level on coolant ex-

pansion tank. When the engine is cold, the

coolant level should be between the marks

Fig. 222 Engine compartment: Coolant

tanks

Fig. 223. When the engine is hot, it may

be slightly above the upper mark.

›››

The vehicle has 2 independent coolant ex-

pansion tanks.

Topping up coolant

»

–

Wait for the engine to cool down.

Fig. 222

›››

1

Coolant expansion tank for the combus-

tion engine cooling circuit.

323

Practical tips

CAUTION

–

Cover the coolant expansion tank cap with

a cloth and carefully unscrew it to the left

However, if the brake fluid level goes down

noticeably in a short time, or drops below

the  mark, there may be a leak in the brake

system. Seek specialist assistance. A warning

light on the instrument panel display moni-

If you run out of coolant in the expansion

tank, park the car in a safe place and do not

continue driving. Obtain technical assis-

tance.

.

›››

Top up the coolant only if there is still cool-

ant in the expansion tank, otherwise you

could damage the engine. If there is no

coolant in the expansion tank, do not con-

tinue driving. You should obtain professio-

tors the brake fluid level page 85 .

›››

In right-hand drive vehicles the brake fluid

reservoir is on the other side of the engine

compartment.

Brake fluid

nal assistance

.

›››

–

If there is still some coolant in the expan-

sion tank, top up to the upper mark.

Changing brake fluid

Check and refill the brake fluid

We recommend that you have the brake fluid

changed by a Technical Service.

Top up with coolant until the level be-

comes stable.

WARNING

Screw the cap back on correctly.

If the brake fluid level is low or unsuita-

ble/old brake fluid is used, the brake sys-

tem may fail or braking power may be re-

duced.

If there is a coolant leak, take the vehicle

specialised workshop to have the cooling

system examined.

●

Check the brake system and the brake

WARNING

fluid level regularly!

●

The cooling system is under pressure. Do

●

When the brake fluid is used and brakes

not unscrew the cap on the coolant expan-

sion tank when the engine is hot: risk of

burns!

Fig. 225 Engine compartment: brake fluid

reservoir cap.

are subjected to extreme braking forces,

bubbles of vapour form in the brake system.

These bubbles can significantly reduce

braking power, notably increasing braking

distance, and could result in the total fail-

ure of the brake system.

The brake fluid reservoir is located in the en-

●

Store the antifreeze in its original con-

gine compartment page 318 .

›››

tainer and keep it out of reach of children.

●

If working inside the engine compart-

Checking the brake fluid level

ment, remember that, even when the igni-

tion is switched off, the radiator fan may

start up automatically, and therefore there

is a risk of injury.

●

Be sure to always use the correct brake

The brake fluid level must be between the 

and  markings.

fluid. Only use brake fluid that expressly

meets the VW 501 14 standard.

324

Checking and refilling levels

●

Check there is enough windscreen water in

●

You can buy VW 501 14 standard brake

Windscreen washer reser-

voir

the reservoir.

fluid at a specialised CUPRA service or at a

SEAT Official Service. If none is available,

use only high-quality brake fluid that meets

DIN ISO 4925 CLASS 4 standards, or USA

Standards FMVSS 116 DOT 4.

Plain water is not enough to clean the wind-

screen and headlights. We recommend that

you always add a product to the windscreen

washer fluid.

Checking the level of the window

washer tank and refilling it

●

The replacement brake fluid must be

new.

Recommended windscreen wipers

●

Brake fluid should be stored in the closed

●

For the hottest seasons we recommend

original container in a safe place out of

reach of children. Risk of poisoning!

summer G 052 184 A1 for clear glass. Propor-

tions of the mixture in the washer fluid tank:

1:100 (1 part concentrate per 100 parts wa-

ter).

CAUTION

Brake fluid should not come into contact

with the vehicle paintwork, as it is abrasive.

●

All year round, G 052 164 A2 for clear glass.

Approximate proportion of the winter mix-

ture, up to -18°C (0°F): 1:2 (1 part concen-

trate per 2 parts water); otherwise, a 1:4 pro-

portion of mixture in the washer fluid tank.

For the sake of the environment

Fig. 226 In the engine compartment: win-

dow washer tank cap.

Brake fluid is an environmental pollutant.

Collect any spilt service fluids and allow a

professional to dispose of them.

The capacity of the window washer tank can

be found in page 360 .

The window washer tank is in the engine

›››

compartment page 318 .

›››

Check the water level in the windscreen

washer reservoir regularly and top up as re-

quired.

CAUTION

If the water from the windscreen washer

does not contain enough anti-freeze, it

may freeze on the windscreen and rear

window, reducing forward and rear visibili-

ty.

The window washer tank contains liquid de-

tergent for the windscreen and rear window.

●

Open the bonnet  page 316 .

›››

●

In winter, ensure the windscreen washer

The window washer tank is marked with

contains enough anti-freeze.

the  symbol on the cap.

●

In cold conditions, you should not use the

»

windscreen wiper system unless you have

325

Practical tips

warmed the windscreen with the ventila-

tion system. The antifreeze could freeze on

the windscreen and reduce visibility.

Keep children away from acid and batteries!

Always follow the instruction manual.

12-volt battery





General information

Disconnecting the battery

CAUTION

The battery is located in the engine com-

partment page 318 or luggage compart-

The battery should only be disconnected in

exceptional cases. When the battery is dis-

connected, some of the vehicle's functions

are lost. These functions will require reset-

ting after the battery is reconnected.

›››

Never mix an unsuitable antifreeze or other

similar additives with the windscreen wash-

er water. A greasy layer may be formed on

the windscreen which will impair visibility.

ment (PHEV hybrid vehicles) page 328

›››

and is practically maintenance free. It is

checked as part of the Inspection Service.

Nevertheless, check the terminals are clean

and have the correct tightening torque, es-

pecially in summer and winter.

●

Use clean water with a window cleaner

recommended by CUPRA.

When disconnecting the battery from the

vehicle on-board network, disconnect first

the negative cable and then the positive ca-

ble.

●

If necessary, add a suitable antifreeze to

All work on batteries requires specialist

knowledge. Please refer to a specialised CU-

PRA Service, SEAT Official Service or a work-

shop specialising in batteries: risk of burns or

exploding battery!

the water in the reservoir.

CAUTION

Deactivate the anti-theft alarm before you

disconnect the battery. Otherwise the alarm

will be triggered.

●

Do not mix cleaning products recom-

mended by CUPRA with other products.

This could lead to flocculation and may

block the windscreen washer jets.

The battery must not be opened. Never try

to change the fluid level of the battery. Oth-

erwise explosive gas is released from the

battery that could cause an explosion.

If the vehicle is not used for long periods

●

When topping up service fluids, make ab-

The vehicle has a system for monitoring the

current consumption when the engine is left

solutely certain that you fill the fluids into

the correct reservoirs. Using the wrong flu-

ids could cause serious malfunctions and

engine damage!

unused for long periods of time page 330 .

›››

Battery warning indications

Some functions, such as the interior lights,

or the remote door opening, may be tempo-

rarily 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.

Wear eye protection.



●

Lack of window washer fluid causes the

Battery acid is extremely corrosive. Wear pro-

tective gloves and eye protection. Rinse any

splashes of electrolyte with plenty of water.



view through the windscreen to be ob-

scured.

Fires, sparks, open flames and smoking are pro-

hibited.



The battery should only be charged in a well-

ventilated zone. Risk of explosion!



326

Checking and refilling levels

Winter conditions

●

Keep children away from acid and batter-

CAUTION

ies.

During the winter, the starting power may be

reduced, and if necessary, the battery

●

Do not expose the battery to direct sun-

●

Before working on the electrical system,

light over a long period of time, as the in-

tense ultraviolet radiation can damage the

battery housing.

should be charged page 329 .

you must switch off the engine, the ignition

and all electrical devices. The negative ca-

ble on the battery must be disconnected.

When a light bulb is changed, you need on-

ly switch off the light.

›››

WARNING

●

If the vehicle is left standing in cold con-

ditions for a long period, protect the bat-

tery from “freezing”. If it freezes it will be

damaged.

Always be aware of the danger of injury and

chemical burns as well as the risk of acci-

dent or fire when working on the battery

and the electrical system:

●

Deactivate the anti-theft alarm by un-

locking the vehicle before you disconnect

the battery! The alarm will otherwise be

triggered.

●

Wear eye protection. Protect your eyes,

skin and clothing from acid and particles

containing lead.

Control lamp

●

When disconnecting the battery from the

vehicle on-board network, disconnect first

the negative cable and then the positive

cable.

●

The control lamp  lights up when the igni-

tion is switched on. It should go out when the

engine has started running.

Battery acid is extremely corrosive. Wear

protective gloves and eye protection. Do

not tilt the batteries. This could spill acid

through the vents.

●

Switch off all electrical devices before re-

Indicator lamps and driver messages on the

instrument cluster display or infotainment

system:

connecting the battery. Reconnect first the

positive cable and then the negative cable.

Never reverse the polarity of the connec-

tions. This could cause an electrical fire.

●

Neutralise any electrolyte splashes on the

skin, eyes or clothing with a soapy solution,

and rinse off with plenty of water. If acid is

swallowed by mistake, consult a doctor im-

mediately.

Defective alternator



3 Valid only for: conventional vehicles.

●

Never charge a frozen battery, or one

which has thawed. This could result in ex-

plosions and chemical burns. Always re-

place a battery which has frozen. A flat bat-

tery can also freeze at temperatures close

to 0°C (+32°F).

●

Fires, sparks, open flames and smoking

are prohibited. When handling cables and

electrical equipment, avoid causing sparks

and electrostatic charge. Never short the

battery terminals. High-energy sparks can

cause injury.

The control lamp lights up RED.

The vehicle battery stops charging from the

alternator. You should immediately drive to

the nearest specialised workshop.

●

Ensure that the vent hose is always con-

nected to the battery.

●

A highly explosive mixture of gases is re-

You should avoid using electrical equipment

that is not absolutely necessary because this

will drain the battery.

●

Never use a defective battery. This could

leased when the battery is under charge.

The batteries should be charged in a well-

ventilated room only.

cause an explosion. Replace a damaged

battery immediately.

»

327

Practical tips

Error: the 12 V vehicle battery

is not charging. Park safely!

and the vehicle should be jump started

The 12-volt power supply is limited, maybe

because the 12 volt battery is discharged or

not working at full performance. The 12-volt

battery can be charged while driving. Until

the warning disappears, you should drive

with care.



page 54 or professional assistance should

be sought.

›››

The control lamp lights up RED.

●

Go to a qualified establishment.

 Stop driving! Stop the vehicle at the next

opportunity and in a safe place.

Have the electrical system checked.

The instrument cluster displays a message

due to a DCDC failure (electrical, mechanical

or energy balance).

Low level of the 12 V vehicle

battery. Charge while driving

Error: 12V power supply. Visit the

workshop



The control lamp lights up YELLOW.

There is a fault in the 12-volt power supply:

●

Switch the ignition off and seek professio-

nal assistance.

●

Go to a qualified establishment.

Starting capacity may be limited. If this driver

message goes out after a certain amount of

time, the vehicle's battery has recharged

while driving and reached a sufficient level. If

the driver message does not go out, take the

vehicle to a specialized workshop.

Have the electrical system checked.

Error: 12V power supply. Park



safely! Check the manual

Access to the 12 volt battery

The control lamp lights up RED.

 Stop driving! Stop the vehicle at the next

opportunity and in a safe place.

Replace the 12V vehicle battery.

Go to a workshop



There is a serious fault in the 12V power sup-

ply.

The control lamp lights up YELLOW.

The 12 volt vehicle battery has almost

●

Go to a qualified establishment.

reached the end of its useful life. Visit a pro-

fessional and request an inspection and re-

placement, if necessary, of the 12-volt vehi-

Have the electrical system checked.

Error: 12 V vehicle battery. En-



cle battery page 329 .

›››

gine cannot be started. Visit the

workshop

Fig. 227 Hybrid vehicles (PHEV): location

of the battery in the luggage compartment

Error: The 12V power supply is

currently limited. Drive with cau-

tion.



The control lamp lights up YELLOW.

The connection between the on-board net-

work and the 12-volt battery has been inter-

rupted. If the drive system switches off in this

situation, it should not be switched on again

The control lamp lights up YELLOW.

328

Checking and refilling levels

Valid for hybrid vehicles (PHEV)

workshop to have the battery checked

and replaced if necessary.

Checking the battery electrolyte

level

The 12-volt vehicle battery is located under

the luggage compartment floor.

Black: The battery’s electrolyte level is cor-

rect.

●

Open the luggage compartment.

Raise the luggage compartment floor

page 142, to gain access to the 12-volt

›››

Charging or changing the battery

battery cover Fig. 227 .

›››

●

A suitable tool must be used to open and

If you often drive short distances or if the ve-

hicle is not driven for long periods, the bat-

tery should be checked by a specialised

workshop between the scheduled services.

close the cover.

Valid for conventional vehicles

●

Raise the bonnet

in Working in the

›››

If the battery has discharged and you have

problems starting the vehicle, the battery

might be damaged. If this happens, we rec-

ommend you have the vehicle battery

checked by a Technical Service where it will

be re-charged or replaced.

Fig. 228 Sight glass on the top of the 12

volt battery (schematic representation).

engine compartment on page 316.

●

Lift the cover that protects the front of the

battery page 318 , Fig. 217 .

›››

The electrolyte level should be checked reg-

ularly in high-mileage vehicles, in hot coun-

tries and in older batteries.

Charging the battery

●

Check the colour display in the "magic eye"

on the top of the battery.

The vehicle battery should be charged by a

specialised workshop only, as batteries using

special technology have been installed and

they must be charged in a controlled envi-

ronment.

●

If there are air bubbles in the window, tap

the window gently until they disperse.

The “magic eye” indicator, located on the

top of the battery changes colour, depend-

ing on the charge state and electrolyte level

of the battery.

Replacing a vehicle battery

The 12-volt vehicle battery has been de-

signed to suit its location and has specific

safety features. If the battery needs to be re-

placed, it is recommended that it be installed

by an official CUPRA qualified workshop.

There are two different colours:

Yellow or colourless: The battery's electro-

lyte level is too low. Go to a specialised

»

329

Practical tips

These workshops have the technical docu-

mentation and equipment required to find

out the size, technology, and maintenance

and safety requirements of the new battery.

that the battery is charged much more effi-

ciently than on vehicles without a power

management system. To maintain this func-

tion after replacing the battery, we recom-

mend that the replacement battery used is

of the same make and type as the original fit-

ted battery. To make proper use of the power

management function after the battery has

been changed, have the battery coded to

the power management mode at a special-

ised workshop.

Energy management

Optimisation of the starting ca-

pacity

 Always use maintenance-free batteries

according to the TL82506 and VW75073

standards. These standards must be from

October 2014 or later.

The power management controls the distri-

bution of electrical energy and thus helps to

ensure that there is always enough power

available to start the engine.

The degassing tube must always be connec-

ted to the hole on the negative pole side and

the hole on the positive pole side must be

sealed.

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.

WARNING

●

Always use only maintenance free batter-

The vehicle’s 12V battery must always be re-

placed by a qualified specialist company, as

the vehicle’s electronics must be adapted

during replacement. In addition, the battery

parameters for functional safety have been

determined based on the original battery.

Only a qualified specialist company has the

right technology to fit the correct replace-

ment battery.

ies that do not run flat alone and whose

properties, specifications and size corre-

spond to the standard battery. The specifi-

cations are indicated on the battery case.

●

Before starting any work on the batteries,

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.

you must read and observe the warnings

in General information on page 327.

›››

For the sake of the environment

The use of unsuitable batteries could inva-

lidate the vehicle registration certificate.

 Batteries contain toxic substances such

as sulphuric acid and lead. They must be

disposed of appropriately and must not be

disposed of with ordinary household waste.

The main functions incorporated in the pow-

er management system are battery diagno-

sis, residual current management and dy-

namic power management.

Start-Stop systems ( page 217 ) are equip-

›››

ped with a special battery. Therefore, it must

only be replaced with a battery of the same

specifications.

Your vehicle is equipped with an intelligent

power management system to control the

Battery diagnosis

The battery diagnosis function constantly

registers the condition of the battery.

distribution of electrical energy page 330 .

›››

The power management function ensures

330

Checking and refilling levels

Sensors detect the battery voltage, battery

current and battery temperature. This ena-

bles the system to calculate the current pow-

er level and charge condition of the battery.

riod. Some convenience functions, such as

remote vehicle opening, may not be availa-

ble under certain circumstances. These

functions will be restored when you switch

on the ignition and start the engine.

Please remember that the power and use-

ful life of the battery are limited.

●

If there is a risk that the vehicle may not

start, the alternator electrical failure or low

battery charge level warning lamp will be

Residual current management

shown  page 327 .

›››

With the engine switched off

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

diagnosis data into consideration.

For example, if you listen to the sound sys-

tem with the engine switched off the battery

will run down.

Flat battery

Starting ability has first priority.

If the energy consumption means there is a

risk that the engine will not start, a text will

be displayed in vehicles with a driver infor-

mation system.

Short trips, 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.

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.

This driver indicator tells you that you must

start the engine so that the battery can re-

charge.

Dynamic power management

When the engine is running

While the vehicle is moving, this function

distributes 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 alter-

nator can supply, and thus maintains the

maximum possible battery power level.

In these situations you will be aware that the

power management system is intervening to

control the distribution of electrical power.

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.

When the vehicle is parked for long peri-

ods

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

current they are using. This limits the

To restore the necessary energy balance, the

system will then temporarily shut off the

electrical devices that are using a lot of pow-

er, or reduce the current they are consum-

ing. Heating systems in particular use a large

amount of electrical power. If you notice, for

Note

●

Neither is the power management system

able to overcome the given physical limits.

amount of power consumed and helps to

ensure reliable starting even after a long pe-

»

331

Practical tips -> Checking and refilling levels for Your Cupra Leon 4 Door First Generation (2020-2026)

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