NC Passenger Seat Alarm Warning

[guyso]

Hello All

I have been following this forum for some time though this is my first post. I hope someone can help as this problem is driving me crazy.

I have a early 2006 NC, Manufactured 12/2005. The passenger seat has a warning alarm which activates if someone is in the seat and their seat belt is not fastened. This alarm is super sensitive, even placing a wallet on the set causes it to go off. What's more it is heat sensitive, the hotter the seat gets the more sensitive it gets. With summer coming on the alarm is now going off even with nothing on the seat.

As a temporary fix I have found an old seat belt buckle which I keep in the seat belt clip to stop the alarm. I have heard the level of pressure required to set off the alarm is able to be calibrated. Even though I have an OBD2 plug in device, I can not work out any way to calibrate this sensor.

Any suggestions really appreciated as this is driving me crazy and I imagine if I take it to Mazda it will cost a fortune.

Hope I have posted this in the correct Section of the Forum. If not please let me know.

Thank very much.

[Mr Morlock]

I dont know the answer though I think I have seen a post on it somewhere. Your fix seems pretty good to me. What would happen if you just left the passenger seat belt in place all the time? 93 clubman usually can find a reference for nearly all subjects so maybe send him a PM if he does not comment.

[93_Clubman]

Topic has certainly been raised on here - one of the more recent responses follows:
http://ww.mx5cartalk.com/forum/viewtopi ... 7&start=15

[guyso]

Thank you Mr Morlock and 93_Clubman. Sorry I have taken some time to get back to you, I have been away on a trip for a while.

I have looked at the links you provided and can not find anything which helps, I have Googled for ages and not found anything. I have also extensively searched these forums and found nothing about the problem I am having. Lots of talk about seat belt retraction and similar, but nothing which helps my problem.

My car appears to have a passenger weight sensor calibration and heat problem. The passenger seat belt warning goes off with the lightest weight on the seat. Even a wallet placed on the seat will set the sensor off. The system seems to think a wallet is a person as fastening the seat belt stops the buzzer. What is worse, when the soft top is down and the seat warms up the buzzer goes off all the time, even with nothing on the seat.

Unlike the US version, my 2005 AUS version does not have a weight sensor on the seat rails. There seems to be some sort of sensor built into the bottom of the seat itself. You can see this in the ribbon cable disappearing into the seat in the following photo I took when the seat was out. The other electrical connections in the photo are for the seat side airbags.

Seat weigth sensor wiring.JPG

Is there a calibration procedure which I can use to desensitize the passenger seat weight sensor? Is there any other solution?

Thanks

[93_Clubman]

Is there a calibration procedure which I can use to desensitize the passenger seat weight sensor?
Assuming you're not happy to plug the seat belt input into the seat belt receiver.
From a quick look, I don't think so, although you could replace the weight sensor.

Is there any other solution?
Mazda dealer or Mazda specialist re desensitising the weight sensor.
Another approach is as per the NC owner glovebox handbook:
'Consult an Authorized Mazda Dealer to deactivate or restore the seat belt minder.'
http://forum.miata.net/vb/archive/index ... 67728.html

'The dealer can disable the warning on either the passenger seat or the drivers seat (or both) via the OBDII diagnostic/setup system. I believe, though I could be wrong, that it's just the beeper that is switchable, the light will come on anyway.'
http://forum.miata.net/vb/showthread.php?t=164349

You might also find this of interest:
'Posted by brmx5fan
I have carried my work bag (laptop and other stuff) in the passenger seat and it does not "chime" at me. The seatbelt and yellow pass airbag light are lit up, but no sound.
Is mine broken??
Posted by Craig Wagner
Mine works the same way. In fact, just yesterday I had someone in the passenger seat. As soon as they sat in the car the seatbelt light came on until they bucked their belt. No chime though.
In fact, on page 2-14 of my owner's manual there is a chart that shows how the seat belt reminder system works. It clearly shows only two cases where the chime will be heard, and both of them are when the driver's belt is unfastened. If only the passenger belt is unfastened you get the light but no chime.
Now the interesting thing about that particular page is that the contents of that page are actually a sticker that was pasted over the original page contents. So maybe some very early production models worked differently I suppose. But I bought mine in October, so it must have been pretty close to one of the first batches to come off the line (at least for N.A. distribution).'
http://forum.miata.net/vb/showthread.ph ... 349&page=2