How do i release a locked safety belt on Hyundai Accent 2007 model

Question edited for clarity, full make model details.
Question moved from Spanish car maker Seat, (pronounced 'See-At') to make model category.

switch on passenger seat base - MBWorld.org Forums

https://mbworld.org > ... > SL-Class (R129)
Feb 2, 2006 - It's for when you put a baby/car seat in. It keeps the seat belt tensioner in one place after the seat belt is activated.
Seat belt locking in position
Feb 28, 2017
SL rear seats - family car, occasionally!?
Feb 24, 2017
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Child Smart Seat for SL ' Mercedes-Benz Forum

https://www.benzworld.org > ... > R129 SL-Class
Jul 10, 2012 - Then there is a button to lock the seat belt of the passenger seat to secure the safety seat on it and deactivate the air bag. That lock button ...
passenger seat belt ' Mercedes-Benz Forum - BenzWorld.org
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Seat belt is too tight ' Mercedes-Benz Forum
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More results from www.benzworld.org

and lastly

https://www.benzworld.org/threads/child-smart-seat-for-sl.1662040/

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the seat belt anchor are activated when the air bags go off, they tighten down the belt so they also need to be replaced

There is no relay for the passenger side air bag . What seams to be the trouble ? There is possibly a code set in the air bag control module .
Air Bag and Safety Belt Pretensioner Supplemental Restraint System (SRS) The air bag supplemental restraint system (SRS) is designed to provide increased collision protection for front seat and second row outboard occupants, in addition to that provided by the 3-point safety belt system. Safety belt use is necessary to obtain the best occupant protection and to receive the full advantage of the SRS.
This vehicle line contains dual stage deployment (advanced restraint system) driver and front passenger air bag modules. These vehicles are also equipped with driver and front passenger safety belt retractor pretensioners. These vehicles can also be equipped with optional side air curtains that deploy from the A-pillar to the C-pillar upon a side impact. Vehicles with optional side air curtains are also equipped with seat side air bag modules in the front seats.
Side air curtains deploy from the headliner, protecting the first and second row outboard occupants during a side impact. Seat side air bag modules deploy from the outboard front seat backrest upon a side impact. In addition, a front impact severity sensor is mounted to the lower radiator support, a seat position sensor is mounted to the driver seat and a usage detection switch is added to the front driver and passenger outboard buckles. If equipped with optional side air curtain modules and seat side air bag modules, there are an additional 4 side impact sensors.
Vehicles are also equipped with an occupant classification sensor (OCS) system as part of the front passenger seat. The OCS system includes 2 OCS rails and an OCS module.
Passenger Air Bag Deactivation (PAD) Indicator
The passenger air bag deactivation (PAD) indicator is a visual indicator used to inform the front seat occupants of the passenger air bag deactivation state. The PAD indicator is a stand-alone lamp installed into the vehicle instrument panel in a position visible to each front seat occupant.
The restraints control module (RCM) controls the state of the PAD indicator through a direct hardwire connection, based on information provided by the occupant classification sensor (OCS) system. The PAD indicator is lit to indicate the passenger air bag module is disabled. An exemption to this is when the front passenger seat is determined to be empty and passenger safety belt buckle unbuckled, and therefore indication of a deactivated passenger air bag module is not necessary. In all other cases, the PAD indicator is unlit when the passenger air bag module is enabled.
When the ignition switch is in the ON position, the PAD indicator prove-out period is initiated by the RCM. The RCM briefly activates the PAD indicator to prove-out the indicator function and verify to the front occupants correct functional operation of the PAD indicator.
The PAD indicator will be lit/unlit within 1.0 to 1.5 seconds of a change of state from the OCS system.
When an OCS system fault is present, the RCM defaults the passenger air bag module to the last valid state received from the OCS system until the ignition switch is turned OFF. If the OCS system fault is still present when the ignition switch is turned ON, the RCM defaults the passenger air bag module to enabled regardless of the size of occupant in the front passenger seat. The PAD indicator will be unlit. For information on the OCS system, refer to Occupant Classification Sensor System in this section.
The following table indicates the passenger air bag status and the PAD indicator status based the size of the front outboard passenger occupant.

do you mean the seat belt pre-tensioner? i would'nt advise investigating airbag/safety system as you might set the air bag off then that would be the end of a car that age ,take to a garage

Check the belt latch,(the short belt you click in and push button to release). It has a sensor in it. Tap and shake it as it may have a foreign object in it. Look under the seat for the connector(s), and make sure they are pushed in all the way and that the wires aren't damaged. If that doesn't help, try disconnecting the connector. If the light and alarm are still on afterwards.....you have two choices. First, replace that part of the belt. Or, try running a jumper wire across the two contacts in the connector but I cant tell you that!!

you can not release the seat belts. They are a one time use, kind of like the air bags. the seat belt fire off and they can only be replaced, but insurance should cover that expense.
if this answered your question please give a thumbs up to help others.

the seat belts will not release, and the air bag light is on
You will need to replace the seat belts that have the air bag wiring hooked up to them, they are supposed to lock in place during a collision.
there is no way around it.

2003 HYUNDAI TIBURON Recall ID from NHTSA: 02V290000 Auto Recall Date: NOV 05, 2002 Vehicle Component: SEAT BELTS:FRONT:BUCKLE ASSEMBLY Model Affected TIBURON Estimated Vehicles Affected: 7382 Recall Details Auto Recall Date: NOV 05, 2002

Vehicle Component: SEAT BELTS:FRONT:BUCKLE ASSEMBLY Estimated Vehicles Affected: 7382 Model Affected2003 HYUNDAI TIBURON

2003 Hyundai Tiburon Defect Summary:ON CERTAIN PASSENGER VEHICLES, THE DRIVER SEAT BELT BUCKLE WIRING COULD BE DAMAGED BY INTERFERENCE WITH THE DRIVER SEAT CUSHION HEIGHT ADJUSTER MECHANISM.

Defect Consequence:DAMAGED DRIVER SEAT BELT BUCKLE WIRING COULD CAUSE THE SEAT BELT WARNING LAMP OR THE SUPPLEMENTAL RESTRAINT SYSTEM (SRS) AIR BAG WIRING LAMP TO ILLUMINATE. IT COULD ALSO CAUSE THE AIR BAG FUSE (CAVITY NUMBER 5) TO OPEN, PREVENTING AIR BAG DEPLOYMENT. NONDEPLOYMENT OF AN SRS AIR BAG IN A CRASH WHERE AIR BAG DEPLOYMENT IS WARRANTED COULD INCREASE THE RISK OR SEVERITY OF INJURY IN A CRASH.

Remedy:DEALERS WILL INSTALL A NEW DRIVER SEAT BELT BUCKLE, IF NECESSARY, AND WILL PLACE A PROTECTIVE COVER OVER THE DRIVER SEAT BELT BUCKLE WIRING TO PREVENT DAMAGE FROM OCCURRING. OWNER NOTIFICATION BEGAN ON MARCH 24, 2003. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT HYUNDAI AT 1-800-633-5151.

Estimated Vehicles Affected: 7382

Notes: HYUNDAI MOTOR COMPANY 056

look to see if you can adjust your seat belt pretensioner to better suit your height. look at the top of your seat belt- ( driver's side up and to the left of your left shoulder ) and see that you can very easily slide up or down your seat belt pretensioner. you are actually supposed to do this and even redo it if you ever readjustt your seat up or down or forward or backwards. believe it or not, your safety airbag light will come on automatically until you adjust your seat belt pretenioner in a way that the sensors read your seat belt to be safely set. naturally, if someone else drives the car he or she might have to readjust the seat belt pretensioner for the sensors to read them as being safely put. do this and the airbag warning light should go out.

i strongly recommend you take your vehicle to your vehicle's local dealer and have the belt removed from the door and then inspect the belt for damage. A damaged seat belt might break when you need it most. Seatbelts and safety are the most important thing!

Happy to help
Have a nice day!
tc