Seatbelt chmes... (1 Viewer)

[Jay H]

Anybody know how a seatbelt chime work? Ya know the ones that "ding ding ding" if you start the car and not put your seatbelt on in like 5 seconds?

My '05 Subaru will do that if I don't immediately put on my seatbelt even when in park. If the engine is statered.

Does it use a contact sensor in the back of the seatbelt receptor or does it use some kind of electric closed circuit with the metal clip?

I'm posting this to a subaru forum but wonder if any car nuts here would know. Don't want to disable the buzzer and wondering if it might be easier just to fake the sensor into thinking it's always on.

Before the PC hounds go ballistic. I always wear my seatbelt, but not always when sitting in my driveway in park and putting CDs in the CD changer.

Jay

 

[Zen Butler]

There may be details on how to deactivate it in your owner's manual. All my Ford manuals have included the sequence.

 

[Brad_Harper]

Most seatbelts I've seen use a hall effect sensor. There is a permanent magnet in the buckle that completes a circuit when it is close enough to the sensor. Do not disable the sensor electrically!!! Your airbag system needs to know if you are truly fastened in or not to deploy the correct size bag. Fooling the system that you are fastened when you are not could cause severe injury.

 

[Jay H]

You mean there are more than one??? Just kidding, I know what you mean, I think. However, I only know of a weight sensor (75lbs) that the subaru uses for the PASSENGER side chair. In fact, it has an indicator on the dash saying that the pass. airbag is on. And that is based on a weight sensor as it states in the manual. As far as the driver side, how does the car know anything other than the seatbelt is fastened or unfasted by the seatbelt sensor??? To me, I don't see how the ECU can determine anything useful other than the seatbelt is on and off, no? Does the airbag NOT go off if the car detects the seatbelt is unfastened? In this case, for me, it is useless cause I always wear my seatbelt, so I don't see any harm for me personally to disable the stupid beeping.

Jay

 

[Brad_Harper]

Most new vehicles have two stage driver and passenger front airbags. The airbag system looks to see where your seat position is, and if your seatbelt is done up to determine which stage to fire. If you are far enough away and your belt is done up the larger explosive will fire in a crash. Otherwise the system defaults to the smaller explosive. The weight sensor in the passenger seat is to turn the passenger bag on or off. If on it also looks at position and belt status.

Now if your car thinks the seatbelt is always buckled and you get into an accident when you are not buckled the bag could cause serious injuries. The explosive force of an airbag is enough to break every bone in your face if your too close. You may always wear your seatbelt but the friend who borrows the car one day might not. The airbag systems in todays cars have pretty sophisticated sensor setup to determine where your body is and what your body type is.

There are also explosives in the seatbelt retractors call pretensioners that need to know whether your belt is fastened or not.

 

[MarkHastings]

Why not buckle it and then get in the car (i.e. sit on the buckled seat)?

Or you can get a replacment buckle and put it in the other end of the seat belt to trick the car into thinking it's buckled.

Again, this would only be for when you're in the driveway and not for driving purposes.

 

[Steve Schaffer]

If you put the key in the accessory position instead of the on position you should be able to listen to the radio or load cds without activating the seatbelt chime. You will have to close the driver's door or the "key in ignition" chime will stay on.