NC 2010 Passenger seat sensor

  1. My model of MX-5 is: NC 2010
  2. I’m based near: Lincoln
  3. I’m looking for technical help or recommendations on:

Hi guys

I’m having issues new to me Passenger seat alarm going off when it’s empty. The only way to stop the alarm is to plug the seatbelt in or unplug a cable from under the seat. As far as I can tell the sensor is a mat within the seat but I’m not 100% sure? Does anyone know if this is fixable or am I just going to have to keep the seat belt plugged in or have a fake clip from eBay plugged in.


When you say “empty”, you’re not putting a bag or anything on it are you?

No. Nothing on it at all. Think ive completed the internet trying to find out about it. :smile:

A simple disconnect the clipped plug under the seat (seat out 4 bolts) clean the contacts with appropriate electrical spray and ensure they are making good contact could solve this problem.
Only additional information is if you have side airbags, it’s best to disconnect the battery first.
Worth a try.

Hi Mick

I’m afraid I have tried that. Managed to get to the cable without taking the seat out…that was fun.

I’m maybe just thinking that the actual sensor is broken in the seat unless anyone else has any ideas or can confirm where the sensor is


Probably in the seat.

You should find out if you search this

You will also need a program to look at the wiring diagrams on that site as Adobe Flash is no longer supported by browsers as of earlier this month. I found that out yesterday, but have been given another program that will display them.
I used Ruffle from here

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My 2009 does this occasionally, It seems to link to when it’s really cold. I tried leaving the seatbelt buckled in but that’s just annoying so the next time it happened I just whacked it hard with my hand a few times. that seemed to work…

Whacked the seat base?

Thanks. I’ll take a look

LOL, sounds like a euphemism! seriously next time it happens and you’re driving just give the seat a few hits with the palm of your hand all over the base. I assume the sensor springs back up or something to say there’s not a person in the seat.

I’ll give it a go. It comes on straight away before I’ve even left my street.

Ah mine comes on randomly

Reviving this thread as this same issue is currently happening in my 2012 NC2.

I’ve also removed the seat and cleaned the electrical connectors with contact cleaner but this hasn’t solved the issue. The seatbelt warning chime continues even if the seat is completely unoccupied!

Is this simply a faulty seat/sensor? Can the sensor be replaced independently from the seat?