• Vehicles with manual transmission: place the gear lever firmly in neutral, depress the clutch pedal completely, and hold it fully down until the engine starts successfully.
• Vehicles with automatic transmission: press the brake pedal firmly down and keep it depressed continuously until the engine starts.
• Press the start button once without touching or pressing the accelerator pedal. A valid, authorized key must be located inside the vehicle interior for the engine of your Seat Leon to start. After the engine starts successfully, the illumination on the button changes from flashing to fixed, confirming that the engine is running.
• If the engine fails to start on the first attempt, stop cranking, wait for approximately 1 minute to allow the system to reset, and try again. If necessary, follow the procedure to perform an emergency start.

Diesel engines can take a few seconds longer than usual to start on cold days while the glow plugs heat up. During this preheating phase, the glow plug warning lamp remains illuminated on the instrument panel. To prevent unnecessary discharging of the 12-volt battery, avoid using any major electrical equipment while the glow plugs are actively pre-heating.

The exact preheating time required depends on current coolant and ambient exterior temperatures. When the engine is already at normal operating temperature, or when outside temperatures are above +8 ºC (+46 ºF), the warning lamp will only light up briefly for about one second. This quick check indicates that you can start the engine of your Seat Leon almost immediately.

Starting a diesel engine after having run out of fuel

If the fuel tank of a diesel vehicle was run until completely empty, starting the engine after refuelling may take noticeably longer than normal—sometimes up to a full minute of cranking. This extended starting period occurs because the fuel system must automatically bleed and eliminate trapped air before fuel can reach the cylinders properly.

WARNING Never leave the engine running in enclosed or poorly ventilated spaces, as there is a severe risk of fatal carbon monoxide poisoning.

• The exhaust emissions contain carbon monoxide, an odourless, tasteless, and colourless poisonous gas that rapidly causes loss of consciousness, asphyxiation, and death.

WARNING Never get out of the vehicle while the engine is running, particularly if a gear is engaged.

Using starter fluid risks severe engine damage and physical injury.

NOTICE

• Attempting to restart the engine immediately while it is still coming to a stop after being switched off can cause serious mechanical damage to the starter motor or flywheel.
• When the engine is cold, avoid high revs, driving at full throttle, or subjecting the powertrain to heavy acceleration loads, as cold lubricants increase internal friction and risk premature engine damage.

For the sake of the environment

Do not warm up the engine while stationary at a standstill. Drive off smoothly right after starting your Seat Leon; this helps the powertrain reach its optimal working temperature faster while significantly reducing harmful emissions.

Note High-consumption electrical equipment is temporarily disconnected during engine cranking to reserve maximum battery power for starting.

• When starting with a cold engine, operational noise levels may briefly increase due to hydraulic valve compensation. This is completely normal and provides no cause for concern.
• When ambient temperatures drop below +5 ºC (+41 ºF), diesel models operating a fuel-powered auxiliary heater may emit small amounts of visible steam or smoke from under the vehicle body.

Turning off the engine

• Bring your Seat Leon to a complete and full stop.
• Vehicles with manual transmission: fully depress the clutch pedal.
• Vehicles with an automatic gearbox: engage the parking lock by pressing the P button on the selector.
• Apply the electronic parking brake to hold the vehicle securely.
• Briefly press the start button to shut down the engine.

Car wash function (hybrid vehicles)

When the ignition is turned off on plug-in hybrid models with neutral gear N selected, the vehicle remains free to roll for up to 30 minutes to facilitate automatic car wash conveyers.

After 30 minutes elapse, if the car remains stationary, the automatic parking lock P engages automatically to prevent rolling. A corresponding warning notification is displayed on the instrument cluster display one minute before this automatic activation takes place.

WARNING Never turn off the engine while the vehicle is still in motion. Doing so can cause immediate loss of vehicle control, leading to severe accidents and life-threatening injuries.

• Supplemental restraint systems, including airbags and seatbelt pretensioners, do not deploy when the ignition is switched off.
• The hydraulic brake servo assistance is disabled when the engine is turned off. Consequently, stopping the vehicle requires substantially greater physical force on the brake pedal.
• Electromechanical power steering does not function when the engine is off, requiring significantly more effort to turn the steering wheel.
• Switching off the ignition while moving may trigger the electronic steering column lock, rendering it completely impossible to steer or control the vehicle.

WARNING Always take the vehicle key with you whenever leaving your Seat Leon. This precaution is vital if children remain near or inside the car, as they could otherwise start the engine or operate motorized systems such as power windows, risking severe injuries.

NOTICE

• When the vehicle stops and the Start-Stop system automatically turns off the engine, the ignition remains active. Always ensure the ignition is fully switched off manually before stepping away from the vehicle to prevent complete battery discharge.
• If the engine has been driven hard or at high speeds for a prolonged duration, extreme heat can accumulate. To prevent thermal damage, allow the engine to idle in neutral for approximately two minutes before switching it off completely.

Note After stopping the engine, the electric radiator cooling fan may continue running for several minutes, even with the ignition switched off. It may also restart automatically if trapped engine bay heat causes coolant temperatures to rise or if the bonnet area is exposed to intense direct sunlight.