Mazda CX-5 Service & Repair Manual: Lap Pre Tensioner Seat Belt [Two Step Deployment Control System]

Purpose

• The lap pre-tensioner seat belts retract and tighten the seat belt webbing to protect the front passengers 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.

• 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 front 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 when a signal is received from the SAS control module, causing gas to form.

2. The gas pressure pushes the piston inside the tube, pulling the lead wire.

3. As the lead wire is pulled, the part of the seat belt attached to the wire is also pulled.

4. The slack in the belt is tightened by the front seat belt being pulled by the lap pre-tensioner seat belt and the seat belt ELR mechanism, restraining the passengers.

After activation

1. After operating (deploying) the pre-tensioner, the lead wire is pulled back. However the front seat belts are locked by activation of the stopper function so that the belt webbing is not released.

2. The restraint force of the seat belt is adjusted by the front seat belt load limiter mechanism, preventing injury to the driver and passenger from seat belt pressure.

Fail-safe

• Function not equipped.