ND boot (trunk) opens while driving and button stopped working

Technical Area Electrics & ICE
1
  1. My model of MX-5 is: __2017 ND 1.5 sport Nav
  2. I’m based near: __East Sussex
  3. I’m looking for technical help or recommendations on: __boot release

Our boot opened several times today whilst driving with absolutely no interaction with the key fob button at the time. The rear underside button has stopped working too.
It also opened on turning off the ignition.
I’ve ordered a new bottom from mx5parts but I wondered if anyone else has had similar and what was the cure?
The fob button does open it.
Tried the spare fob and that opens the boot but the external button still doesn’t work when in close proximity etc.

2

Please let me know how you get on with this as mine is known to play up from time to time!!!

2 Likes
3

I had that but also had A LOT more issues and found it was due to a fault ESU (Electrical Supply Unit - computer in the top left of the passenger footwell).
Hopefully yours isn’t related but might be worth a check of a few other aspects:

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4

I see this now :joy:

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5

Thank you. I had a look at that esu a while back when I had window trouble that turned out to be sensors in the motor and I remember it being impossible to get to. How did you get to it? Was it a main dealer repair?

6

I got mine out and back in myself, been in there a few too many times tinkering…

In short:

  1. Floor mat out
  2. Carpet back
  3. Sub enclosure loose
  4. Cover off
  5. ESU unclipped

More details can be found here:

And here:

7

All I gotta do is find one. It’s worrying as I don’t want it to pop the boot when we’re away from the car, that may not happen but it is something I’ve thought about.
When you mentioned esu I thought it was the one that’s higher up under there, that one I can get to so it should be easy enough once sourced.
Did you have to do any clever resets afterwards.

Thank you for your input. :partying_face:

8

Nope, I just replaced the unit, started the car and everything was fine, no coding needed or anything but it isn’t a cheap unit at ~£300 and that included a discount as I have a service plan.
I would check all the other aspects I mentioned in my thread when this occurs to see if it is definitely the ESU or something else.

9

Thank you very much!

10

Strangely today it seems to behave normally and everything is back to normal.
Maybe the sun being out yesterday helped warm up a damp spot and that cured it. Will provide updates if it reoccurs.
I love that this forum allows so much information exchange. It’s really helped me with several options and just having a post like this hanging around could help someone in the future.

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