Seat belt warning in all seating positions

Unfastened front and rear seat belt warning system

Prompts all vehicle occupants to fasten their seat belts.

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To prompt all vehicle occupants to fasten their seat belts, and to notify the driver that all the passengers have fastened their seat belts.

The system first warns the driver visually and then acoustically.

Once the vehicle occupant has fastened their seat belt, if the seat belt then becomes unfastened, the system alerts the driver by generating an acoustic and visual warning.

This lets the driver know which vehicle occupants are actually wearing their seat belt.

How it works

When the driver turns on the ignition, the vehicle reminds the driver to put on their seat belt using the icons displayed on the vehicle’s dashboard.

Once the vehicle has begun to move, having traveled a maximum distance of 500 meters or exceeded a speed of 25 km/h, the system begins to emit an acoustic reminder while a light indicates which seats are not buckled up.

To increase the alert level, if the seat belt is still not done up, the volume of the audible warning increases as time elapses.

When the seat belt is fastened correctly, a switch is pressed which closes an electrical circuit, turning off both the light and the acoustic unfastened seat belt indicator, thereby confirming that the seat belt has been fastened.

The front passenger seat is equipped with an occupancy sensor connected to the seat belt warning system as well as the front passenger airbag system, so this is not triggered in the event of an accident when the seat is not occupied, or to activate the alarm if the seat is occupied and the belt is not in use. This system is not always available for the rear seats; if it is available the warning procedure is similar to that of the front passenger seat; if not, the system is able to detect that a rear door has been opened or that the seat belts have been buckled and are then unfastened while the vehicle is in motion, indicating that the seat is occupied.


  • Belt buckles with a fastened belt sensor, which can range from a simple switch operated by the buckle itself to sophisticated electronic sensors.
  • Presence sensor, at least in the front passenger seat.
  • Acoustic reminder and alert warning.
  • Visual warning to identify which seat belt is unbuckled.


  • Seat belt use protects vehicle occupants by minimizing personal injuries in crashes and limiting these injuries as a result of hitting the interior of the vehicle or being projected out of the vehicle.


In the event of a crash, the probability of death is reduced by 45-50% if the seat belt is fastened in the front seats and by 25% in the rear seats, with the same effect on the prevention of serious injuries.

On interurban roads in 2020, 69% of fatalities among car and van users aged 12 and over were wearing seat belts, and on urban roads 63% of fatalities were wearing them (Directorate General of Transport and Traffic (DGT) data).

Seat belt use is mandatory in all vehicle seats and on all types of roads.

Precautions for use

This system only reminds you to fasten your seat belt by means of an acoustic warning.


The seat belt warning system has been mandatory since 1/11/2014 for the driver’s seat in passenger cars (UN/ECE Regulation No. 16) and work is underway to make seat belt reminders mandatory for all seating positions.

The EuroNCAP program promotes the installation of seat belt warnings for all rear seats in addition to presence detectors.