Information relating to brake assist systems

Advanced brake assist systems integrated into your Seat Leon are engineered to actively support the driver in critical dynamic driving or emergency braking situations. However, the driver always remains fully responsible for maintaining safe control of the vehicle at all times.

When the active brake assist systems are modulating the brakes, you may notice the brake pedal moving on its own or producing mechanical noises. Even in these active regulation phases, you should continue to brake with the necessary force and steer to control the trajectory of the vehicle if required.

• The Electronic Stability Control (ESC), Anti-lock Braking System (ABS), and Traction Control System (TCS) can only operate correctly and harmoniously if all four wheels are fitted with the stipulated, matching tyres.
• If a functional fault occurs within the ABS module, related systems such as ESC, TCS, and the Electronic Differential Lock (EDS) will also cease to function temporarily.

Electronic Stability Control (ESC)

Electronic Stability Control (ESC) helps significantly to reduce the risk of skidding and improves overall directional stability in critical or dynamic driving situations.

Traction control (TCS)

The Traction Control System (TCS) reduces drive torque on wheels that are beginning to spin or skid, adapting power delivery to suit prevailing road surface conditions. TCS facilitates smooth starting, acceleration, and hill climbing.

Electronic brake pressure distribution (EBV)

Electronic Brake force Distribution (EBV) regulates the proportion of braking force distributed dynamically between the front and rear axles. Excessive braking force on the rear axle is prevented, ensuring your Seat Leon remains stable during heavy braking.

Anti-lock braking system (ABS),

The Anti-lock Braking System (ABS) prevents the wheels from locking up under heavy braking right up until shortly before the vehicle comes to a complete stop, helping the driver maintain steering control over the vehicle.

Brake assist (BAS)

Brake Assist (BAS) can help to shorten emergency stopping distances. Brake Assist automatically increases braking pressure to maximum levels if the driver depresses the brake pedal quickly and forcefully in an emergency.

Electronic differential lock (EDS and XDS)

The Electronic Differential Lock (EDS) automatically applies the brakes to spinning wheels and redirects the engine drive force to the wheels with better traction.

The XDS electronic differential lock further enhances traction and handling stability by selectively braking the inside wheel during fast cornering to improve cornering agility.

Multi-collision brake

The multi-collision brake system automatically initiates controlled braking if the airbag control unit detects an initial impact or collision during an accident, helping to prevent secondary collisions.

Automatic braking requirements:

• The driver's foot is not pressing down on the accelerator pedal.

Trailer stabilisation

Keep in mind that a vehicle-trailer combination naturally has a physical tendency to snake or sway at speed. When trailer snaking is detected by the ESC system through vehicle sensors, it automatically applies controlled braking to the towing Seat Leon within system limits to stabilise the entire vehicle-trailer rig.

Electromechanical brake servo (eBKV)

With the ignition switched on, the electromechanical brake servo (eBKV) supplements the physical force applied by your foot, boosting the pressure exerted on the brake pedal. When an advanced driver assistance system initiates braking—such as Adaptive Cruise Control (ACC) regulating speed or during autonomous emergency braking—the brake pedal may move automatically.

After the ignition is switched off, the assistance provided by the brake servo progressively diminishes. If you attempt to hold the stationary vehicle in place using only the brake pedal after shutdown, advisory messages will appear on the instrument cluster display, indicating that brake servo assistance is now restricted.

Once the vehicle has come to a complete halt, always ensure the car is securely immobilised using the parking brake to prevent unintended movement.

Brake blending

In hybrid or electrified models, regulated brake blending seamlessly combines the regenerative braking effect of the electric motor during energy recovery with traditional mechanical friction braking applied by the driver.

WARNING Smart brake assist technology cannot defy the fundamental laws of physics and operates only within established physical and system boundaries.

Driving at excessive speeds on icy, snowy, slippery, or wet road surfaces can cause a sudden loss of vehicle control, leading to serious injuries for the driver and passengers.

• Always adapt your speed and driving style to suit ambient visibility, weather conditions, road surfaces, and traffic flow. Never take risks that compromise safety.
• Brake assist systems cannot prevent a rear-end collision if you are driving too close to the vehicle ahead.
• Always equip your vehicle with suitable tyres. Driving stability and stopping power depend directly on tyre grip.

WARNING The effectiveness of the ESC can be severely compromised if vehicle components or systems affecting driving dynamics are improperly maintained or modified. This degradation is particularly likely if unauthorised changes are made to the suspension or if non-approved wheel/tyre combinations are installed.

• Ensure that all vehicle conversions, tuning, and structural modifications are performed exclusively by specialized workshops.
• Always use approved, suitable tyres, as vehicle stability relies entirely on proper tyre adhesion.

WARNING Driving without brake servo assistance or with restricted brake servo functions can dramatically increase stopping distances and cause severe accidents and injuries.

• If the brake servo fails, the brake pedal requires significantly more physical effort to press, and stopping distances will lengthen considerably due to the lack of power assistance.

Connecting and disconnecting the ESC and TCS

The Electronic Stability Control (ESC) system in your Seat Leon is automatically switched on every time the engine is started. It operates exclusively while the engine is running and encompasses integrated sub-systems including the Anti-lock Braking System (ABS), Electronic Differential Lock (EDS), and Traction Control System (TCS).

The TCS function should generally remain active, and should only be switched off manually in rare, specific driving situations where allowing a controlled amount of wheel slip is necessary to gain traction.

Disconnecting and connecting the TCS

• The Traction Control System (TCS) can be turned on or off directly through the central infotainment system: press the main function button > Driver assist > Smart Assistants.

When the TCS is manually switched off, the dedicated yellow control lamp lights up clearly on the instrument cluster display.

Note If the Traction Control System (TCS) is switched off, the cruise control function is automatically deactivated for safety reasons.

Troubleshooting

The electromechanical brake servo is not working

Stop driving

The warning lamp lights up in red.

A descriptive message is displayed on the dash as appropriate. You must depress the brake pedal with significantly greater force because the braking distance will increase dramatically due to the complete lack of power assistance from the brake servo.

• You should pull over safely and obtain professional technical assistance immediately.

There is a fault in the electromechanical brake servo

The control lamp lights up in yellow.

An advisory message is displayed on the instrument cluster for a few seconds.

Depressing the brake pedal may cause unusual mechanical vibrations.

The brake pedal has to be pressed harder than normal because stopping distances will lengthen due to reduced brake servo assistance.

• Contact a specialized workshop promptly to have the system inspected.

The ABS does not work properly or does not work at all

The control lamp lights up in yellow on the display.

• Contact a specialized workshop without delay. Note that the vehicle's standard friction brakes will still function even without the ABS active, but wheels may lock during hard braking.

The ESC or TCS is regulating

The control lamp flashes yellow, indicating that the stability or traction systems are actively stabilizing your Seat Leon.

ESC fault

The control lamp lights up in yellow, and the Electronic Stability Control has been switched off automatically.

A system fault or defect has been detected.

• Turn off the ignition completely and then switch it on again to reset the sensors.
• If possible, drive your Seat Leon carefully for a short distance at 15–20 km/h (9–12 mph).
• If the control lamp remains illuminated, take the vehicle to a specialized workshop immediately.

The brake assist systems make noises

When the described brake assist systems actively intervene to stabilize the car, you may hear mechanical humming or clicking noises from the engine bay or brakes.

WARNING

• When the ignition is switched on, the functional status of the brake system and all associated brake assist functions is automatically checked. The control lamps on the instrument cluster light up briefly during this self-test and then go out. Any indicator lamp that remains illuminated indicates a functional fault. Seek qualified technical assistance immediately.
• If the brake system warning light comes on simultaneously with the stability control lamp, the ABS regulation function may fail, causing the rear wheels to lock up relatively quickly during heavy braking. This can lead to a sudden loss of vehicle control! If traffic allows, reduce your speed and drive slowly and carefully to the nearest specialized workshop to have the brake system inspected.

  During this journey, avoid heavy braking manoeuvres and sudden steering movements.

• If the indicator lamp does not go out upon starting or lights up while driving, it means that the ABS function cannot operate properly, is unavailable, and will not provide anti-lock protection during braking. Proceed to a specialized workshop as soon as possible.