- My model of MX-5 is: 2019 MX5 RF
- I’m based near: UK
- I’m looking for technical help or recommendations on: Boot release button malfunction
Hi all, having a weird issue with my boot release button.
When using the fob, the boot opens just fine every time. When pressing the external boot release button, the boot does not open, however, it then reliably opens at some random time afterwards (often when the ignition has been fired and the car is moving, or the next day after starting the car).
Obviously I have stopped pressing that button as it’s a serious safety issue to have the boot open at random moments. That gets around the fault, however I do need to get this fixed. If anyone has seen this fault before, would very much appreciate a steer before shelling out for an auto electrician.
Sounds like a mechanical problem with the actual switch. Is sounds like it needs exercise, or maybe replacement.
David
Yeah I thought this at first, but the button doesn’t work even when giving it a pretty robust workout. Struggling to figure out how it could be actuating after the fact on this basis, and have resigned myself to it being some sort of network related issue.
Unless someone has seen the same issue, and short of disassembling the bumper, I guess it’s time to send to the garage.
This Manual pages - MX5 Manual | Mazda MX5 (Mk4) 2015+ suggests that the switch is a simple earth trigger.
I would search for the wires in the boot (the colours are on the link) and check for a good ground and that there is power at the other wire. You could check the switch with a meter and then try mimicking the switch with a quick touch to ground.
The wires for the actuator are also shown so some checking of this could also be done.
Obviously if you are not competent or confident enough to play with these items then best leave alone.
The link to the wiring diagrams should be useful for an auto electrician if you go down that route.
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Sorry, I dont get any joy with that link.
But the system does seem to be over-engineered. What I dont understand is how the action can be delayed by as much as a day, according to psycho_terror.
David
Link works for me.
Based on that wiring diagram I can understand how it could be a mechanical failure at least. Even if the switch itself is fine, if it has a loose earth connection, it won’t work, so I could strip out the lining and have a look at that relatively easily.
The late actuation remains the most confusing part though, and I cannot see how a loose earth could cause it.
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Could be moisture in the switch causing it to short across the contacts intermittently.
I will check this, though I’d have thought if this was the case it would go off all the time, randomly, but it’s very consistent and only actuates at some time after having been pressed…
Hi David,
The link in your post works for me so may be try a different computer.
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Thanks! I found the page anyway, but am none the wiser about a solution to the problem. Why does such a simple function have to be implemented in so complicated a manner? 
David
If you are not familiar with using a multimeter to check wiring then you will have to seek out someone who is in order to identify where the problem is. Sorry.
Max,
I myself am am more than familiar with multimeter use, but the problem is on psycho_terror’s car!
Best,
David
Hi all. Thanks for suggestions on this.
Took me a long time of both trying and failing to diagnose this issue, and willfully ignoring the problem while I dealt with more important stuff before I eventually resolved this. Thought I would report back in case other have the same symptoms.
The issue was caused by a flooded connector behind the rear passenger side wheel arch (clipped to the reverse lamp). This is a wet area, and road debris and water gets flung into this area by the tyres, I assume at high enough pressures to get past the weatherproofing on the connector. I disconnected, blew it out with compressed air, and reconnected, and that was sufficient to restore proper functionality.
I expect this is an issue which could potentially affect all vehicles with the same wiring at some point, however, it’s worth noting that my rear bumper was removed and re-fitted early in the car’s life, so although it seemed to be fully home when I checked it, perhaps the connector was not properly secured during that process.
Regardless of the cause, this is the fix, and apart from having to lie down to access the affected connector, it’s an easy 5 min job. Might be worth doing as preventative maintenance before it manifests, no doubt a blob of dielectric grease on the pins will help a lot.
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