Auto-closing windows

2017 Fiat 124 Spider Abarth Convertible

Fiat 124 Spider switch assembly

Desired outcomes:
Unlatch open top to close > window goes down less than an inch, rather than half-way
Latch closed top > either close windows then, or when the lock button is activated
Unlatch closed top to open > window opens all the way, rather than half-way

I noticed in this video showing how the windows are controlled while the MX-5 RF top is being opened and closed (at least outside the North America market):

  • windows (if closed) only drops less than an inch prior to both opening and closing the top
  • windows return to the fully closed position after the top is closed (as long as you keep the “Close Top” button engaged)

After all, if you are caught in a rain storm, why would you want the windows to open halfway while you are closing the top?  But, that is minor in comparison to the window being left halfway down (or all the way down) while you are in the process of closing the top and exiting the car as the soft top currently behaves.  I’m sure it has something to do with U.S. laws resulting from someone getting their fingers injured while the windows were closing on their own.

It would seem that the logic we desire already exists in the module, since the desired movements already occur while the door is being opened and closed:

  • Open door with windows closed > windows go down less than an inch.
  • Close door with windows closed > windows return to the fully closed position.

That is why I’m following the progress of sergey’s (known as ssh16) “Automatic roll-up windows” project, especially when hitting the lock button while the top is closed) on either:

  • the key fob remote
  • or the exterior door handle (with advanced keyless entry option)

The exterior door handle lock button is my preferred lock procedure, since I turned off the walkaway automatic door lock feature and I never need to remove the remote from my pocket. Ideally though, I feel that the windows should close as soon as the top is latched into the closed position.

Ideally, no extra modules/hardware should be required; I hope instead that it just requires a addition/triggering of code or perhaps we’ll have to exchange the window switch module from another market (or Mazda vehicle) that also has the door lock function (Europe MX-5 does not), since that logic may also be programmed into the same module.

⇓  The European 124 window switches do not have the door lock switch, so I bet they don’t have the door locking options in the Infotainment system either.

euro 124 window switch

⇓  Sergey, keep in mind that even though the underlying switches in the 124 Spider (shown in top photo and directly above) are the same as the Miata’s (shown below), hopefully they are easily separated from the trim bezels, so that the new part you develop may work with both versions in both vehicles 😉


Miata MX-5 switch assembly

Sergey also has another project Key Fob Controlled Windows that may prove to be more popular, and less expensive.  His demo video is below.

In his current implementation,  when you double-click on the lock button, the windows will go up, and when you double-click on the unlock button the windows will go down.  Communication with the window switch is done over the LIN circuit, which goes between the two doors.

13 thoughts on “Auto-closing windows

  1. I can confirm that the vehicles shipped into Canada behave in the same manner. After closing the soft top, I have to manually raise both windows to close them. Most times I forget and then have to turn the power for accessories back on to close them. It’s an annoyance, and I’m honestly unsure why the feature is set up in that manner. I too will gladly make the tweak to correct this once it becomes available.

    Liked by 1 person

  2. Thanks Cal. I changed “at least outside the U.S. market” to “at least outside the North America market”. As much as I too would like it, I doubt that a tweak will be able to resolve this. It will probably require a hardware swap, unless the dealer can make the change via the ODB2 port.


    • Unfortunately there is no way to use ODB2 for this purpose. MX-5 CAN bus simply do not go inside door. For sure Mazda could update this switch using debug tool. Using door handle button also problematic, because its wires do not go inside switch. See my updated blog.


  3.  “Sergey, keep in mind that even though the underlying switch in the 124 Spider (shown in top photo) is the same as the Miata’s, hopefully it is easily separated from the trim bezel so that the new part you develop may work with both vehicles”

    I believe it is same part NA1J66350B. It is very easy to swap it, 15 minutes max. The only problem, that this part is very expensive, list price $250 and with best discount I found $180, plus shipment. For now it is just DYI project, for people with soldering skills. I can provide preprogrammed microcontroller with wires attached and instruction.
    Hacking existing processor will be best solution, but just debugging/programming tool for it cost $170 and it is very complicated task to do.


  4. My daughter pointed out to me today that even if you’ve powered the car down, the window buttons will still operate if you haven’t opened the door yet. While not ideal, at least this lets you close them without having to start the car again.


    • Yes, that’s correct – for about 40 seconds as Sergey stated in his article. PIA always reminding the passenger to keep their door closed a moment longer though 😉


  5. Sergey posted more good news today:

    I was able to figure out CAN messages from fob keys, this makes possible (with external microprocessor) to control windows from the key, when you lock or unlock the car. This will be my next project.


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