Knowledge Base

Free to use workshop manual for your 2015+ Mk4 'ND' Mazda MX-5
Home

 

< Previous   Next >

LAP PRE-TENSIONER SEAT BELT [TWO-STEP DEPLOYMENT CONTROL SYSTEM]

Purpose

  • The lap pre-tensioner seat belt retracts and tightens the belt webbing (between buckle and lap pre-tensioner seat belt) against the occupant's upper torso to hold the occupant firmly in the seat and protect the occupant during a collision.

Function

  • The lap pre-tensioner seat belts operate (deploy) based on the operation signal from the SAS control module to instantly retract and tighten the belt webbing, restraining the driver and passenger.

  • The lap pre-tensioner seat belts operate in conjunction with the pre-tensioner seat belts.

Construction

  • The lap pre-tensioner seat belts are installed to the anchors of the seat belts.

  • The lap pre-tensioner seat belts consist of the following parts shown in the figure:

Operation

Lap pre-tensioner activation
1. The gas generator emits a spark (1) when a signal is received from the SAS control module, causing gas to form.
2. The gas pressure (2) pushes the piston (3) inside the cylinder, pulling the lead wire (4).
3. As the lead wire is pulled, the part of the seat belt attached to the wire is also pulled (5).
4. The slack in the belt is tightened by the seat belt being pulled by the lap pre-tensioner seat belt and the seat belt ELR mechanism, restraining the passengers.

After activation
1. After the pre-tensioner operates, the lead wire (2) is pulled back by the tensional force (1) of the seat belt, and the belt is prevented (locked) from being pulled out by the ball (3) being inserted into the piston (4).
2. The restraint force of the seat belt is adjusted by the seat belt load limiter mechanism, preventing injury to the driver and passenger from seat belt pressure.

Fail-safe

  • Not applicable

< Previous   Next >
 

Free to use workshop manual for your 2015+ Mk4 'ND' Mazda MX-5

COPYRIGHT NOTICE:
This fan site is not affiliated with Mazda, and is intended for personal, or commercial use only. The content of our web pages is for general information purposes only and is presented “as is”. We give no assurance or warranty regarding the accuracy of the contents. Readers should do their due diligence and seek the advice of an appropriately certified automotive technician before attempting any steps on this site. Original content provided by Mazda North America. The content of the manual is copyright under DMCA to: full.metal.resistor@gmail.com
LIMITATION OF LIABILITY:
We accept no responsibility for errors, inaccuracies, or omissions found on these pages. Additionally, we hereby exclude liability for any demands, claims, damages or losses of any kind with regard to any content or information provided on our web-site, including but not limited to incidental or consequential damages, direct or indirect loss, compensatory damages, loss of profits, or otherwise. By using this manual you assume full liablity for any procedures carried out on your vehicle, and are responsible for the vehicle remaining road legal and safe.