Q: What does a seat belt pretensioner do?

asked by on December 14, 2015

What does a seat belt pretensioner do?

Seat belts are lifesaving devices, but technology has evolved beyond the point where these were just static belts that held you in place during an impact. Seat belt pretensioners are used on the driver and passenger front seat belts to help reduce the chance of injury. Here’s what they do:

  1. The pretensioner works with the seat belt retractor.

  2. The pretensioner will not automatically engage in all impacts (only certain types of impact).

  3. When deployed, smoke will come from the pretensioners. This is normal.

  4. The pretensioner is designed to tighten the belt during impact, but then allow the belt to release afterward.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Car barely going and dying

This can be caused by a number of different problems. Most of the time it occurs when the fuel pressure is low due to a failing fuel pump. It can also be a bad sensor, such as the air flow...

How do I switch between the rearview mirror day and night setting?

The rearview mirror has two settings: day, and night. The night setting is designed to reduce glare from bright headlights, and should always be used at night. It also provides less clarity, so it should never be used during the...

When I start the car up it still doesn't move when in drive or reverse

A few things can cause the vehicle to not move in any gear. Most vehicles today are drive-by-wire. There is no mechanical connection between the gas pedal and the engine. Electronic sensors at the gas pedal signal electronic sensors at...

Related articles

How Air Bags Work
Designed Designed to protect the occupants of a vehicle in the case of an accident, air bags inflate when the vehicle collides with another object, or otherwise suffers a sudden deceleration. Absorbing the energy of the impact, vehicle owners need...
2012 Toyota Tacoma vs. 2012 Nissan Frontier: Which One Should I Buy?
The smaller truck category includes those vehicles for men (and women!) who just want to scoot around town but who are opposed to driving a small car and just prefer a truck. These relatively fuel-efficient vehicles offer little in the...
2012 Mazda CX-5 vs. 2012 Toyota RAV4: Which One Should I Buy?
Mid-size crossover SUVs are an excellent option when you need to take several friends along with you, or bring your kids along and yet still need to keep a tight leash on your purchase cost as well as your ongoing...