Pre-Tensioner Systems: Design & Function

Created: September 1, 1999

Subject: Supplemental Restraint Systems Topic: Seatbelt Pre-tensioners Objective: Understand the design and function of seatbelt pre-tensioner systems. Task: While visually inspecting a current model-year vehicle selected from the...

Rescuers must learn to remove interior roof pillar trim before cutting. This Volvo S80 B-pillar has both a pre-tensioner and a side-impact airbag crash sensor.
Rescuers must learn to remove interior roof pillar trim before cutting. This Volvo S80 B-pillar has both a pre-tensioner and a side-impact airbag crash sensor.
This view of a 1999 Volvo S80 display vehicle reveals how B-pillar cuts are typically made where pre-tensioners are now located.
This view of a 1999 Volvo S80 display vehicle reveals how B-pillar cuts are typically made where pre-tensioners are now located.
The tube-style pre-tensioner fires during a collision to pull the slack out of the lap/shoulderbelt assembly.
The tube-style pre-tensioner fires during a collision to pull the slack out of the lap/shoulderbelt assembly.

Extrication crews should avoid cutting into a seatbelt pre-tensioner unit. To do this, we must first locate the units. Typically they are on or inside the vehicle’s B-pillar or are secured to the rocker channel at the seatbelt spool mechanism.

The best way to identify them is to strip away the interior plastic trim of the B-pillar before cutting into it. Any cutting or spreading along the rocker channel that is near the seatbelt spool should also be done with caution.

General Motors publishes an 18-page booklet explaining its airbag systems and their pre-tensioners. The publication, titled Air Bags and Pre-Tensioners in GM Vehicles, is available free of charge by calling the toll-free telephone number 800-393-4831 and following voice prompt 2. The booklet is item number 22008.22-Q2 and is free of charge for single copies to an agency.

TABLE OF PRE-TENSIONERS (1999 model year)

· Acura 3.2RL & 3.5RL Seatbelt pre-tensioner (2) at front three-point seatbelts.

· Audi A-4 Seatbelt pre-tensioner (5) at all seatbelts.

· Audi A-6 Seatbelt pre-tensioner (5) at seatbelts.

· Audi A-8 Seatbelt pre-tensioner (5) at all seatbelts.

· BMW 3-series (323 & 328 models represent six vehicle types) Seatbelt pre-tensioner (4), all three-point seatbelts, at female buckle.

· BMW 5-series (528 & 540 models represent five vehicle types) Seatbelt pre-tensioner (5), all three-point seatbelts, at female buckle.

· BMW 7-series (740 & 750 models represent five vehicle types) Seatbelt pre-tensioner (5), all three-point seatbelts, at female buckle.

· BMW M-series (M, M3 & M5 models represent five vehicle types) Seatbelt pre-tensioner (5), all three-point seatbelts, at female buckle.

· BMW Z-series (Z3 models represent three vehicle types) Seatbelt pre-tensioner (2), at female buckle.

· Cadillac Catera Seatbelt pre-tensioner (2), front three-point seatbelts.

· Cadillac Seville Seatbelt pre-tensioner (2), front three-point seatbelts.

· Chevrolet Prism LSi Seatbelt pre-tensioner (2), front three-point seatbelts.

· Chevrolet Venture minivan Seatbelt pre-tensioner (2), front three-point seatbelts.

· Ford Econoline van Seatbelt pre-tensioner (2), front three-point seatbelts.

· Infiniti G20 Seatbelt pre-tensioner (2), front three-point seatbelts.

· Infiniti I30 Seatbelt pre-tensioner (2), front three-point seatbelts.

· Infiniti I45 Seatbelt pre-tensioner (2), front three-point seatbelts.

· Jaguar XJ, XK, Vanden Plas and S-series - 2000 model year (models represent seven vehicle types) Seatbelt pre-tensioner (2), front three-point seatbelts, 1995 and newer.

· Land Rover Discovery II SUV Seatbelt pre-tensioner (2), front three-point seatbelts.

· Lexus 300 & 400 sedan series(models represent six vehicle types) Seatbelt pre-tensioner (2), front three-point seatbelts.

· Mercedes C-class (models represent 3 vehicle types) Seatbelt pre-tensioner (2), front three-point seatbelts.

· Mercedes CLK-320, 430 coupes Seatbelt pre-tensioner (2), front three-point seatbelts.

· Mercedes CLK Cabriolet 320 two-door convertible Seatbelt pre-tensioner (2), front three-point seatbelts.

· Mercedes E-class (models represent five vehicle types) Seatbelt pre-tensioner (2), front three-point seatbelts.

· Mercedes S-class (models represent two vehicle types) Model year 2000 - Seatbelt pre-tensioner (2), front three-point seatbelts.

· Mercedes SL-class coupe & roadster (models represent four vehicle types) Seatbelt pre-tensioner (2), front three-point seatbelts.

· Mercedes SLK 230 Kompressor coupe/roadster Seatbelt pre-tensioner (2), front three-point seatbelts.

· Mercedes ML320, ML 430 SUV Seatbelt pre-tensioner (2), front three-point seatbelts.

· Oldsmobile Silhouette minivan Seatbelt pre-tensioner (2), front three-point seatbelts.

· Pontiac Montana minivan Seatbelt pre-tensioner (2), front three-point seatbelts.

· Rolls-Royce Seatbelt pre-tensioner (2), front three-point seatbelts, 1995 & newer.

· Saab 9-3 & 9-5 models Seatbelt pre-tensioner (2), front three-point seatbelts.

· Subaru Outback (model year 2000) Seatbelt pre-tensioner (2), front three-point seatbelts.

· Toyota Corolla Seatbelt pre-tensioner (2), front three-point seatbelts.

· Toyota Sienna minivan Seatbelt pre-tensioner (2), front three-point seatbelts.

· Toyota Solara Seatbelt pre-tensioner (2), front three-point seatbelts.

· Toyota Tacoma & Pre-Runner pickups Seatbelt pre-tensioner (2), front three-point seatbelts.

· Volkswagen New Beetle Seatbelt pre-tensioner (2), front three-point seatbelts.

· Volkswagen Cabrio Seatbelt pre-tensioner (2), front three-point seatbelts.

· Volkswagen Golf Seatbelt pre-tensioner (2), front three-point seatbelts.

· Volkswagen GTI Seatbelt pre-tensioner (2), front three-point seatbelts.

· Volkswagen GLX Jetta Seatbelt pre-tensioner (4), front and rear three-point seatbelts.

· Volkswagen Passat Seatbelt pre-tensioner (4), front & rear three-point seatbelts.

· Volkswagen Passat GLS wagon Seatbelt pre-tensioner (2), front three-point seatbelts.

· Volvo S40, S70, V40 & V70 Seatbelt pre-tensioner (4), front & rear three-point seatbelts.

· Volvo C70 convertible Seatbelt pre-tensioner (4), front three-point seatbelts.

· Volvo S80 Seatbelt pre-tensioner (5), all three-point seatbelt locations.

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