Seat heater stops working every ~one drive in 20

[Obioban]

So, randomly, so far only at seat heater level 3, my seat heater will turn off and not work for the rest of the duration of the drive.

Next drive it's as if nothing happened-- works perfectly.

I assume this means it's not a short in the seat heater pad, as in other cars a short in the seat heater pad blows a fuse in the seat heating system-- and coming back to life means it hasn't blown any fuses.

Any thoughts as to what could be causing this?

 

[3pete]

I have a similar issue though mine is on any seat heat level and it pretty reliably cuts out after a few minutes, refusing to turn on until I park the car for a bit, but then it is fine to go for another few minutes so clearly no fuse has blown. It seems like there is some sort of monitoring to shut off the seat in addition to the fuse.

I think this video outlines one step you could take to troubleshoot whether there is 0.0 ohm resistance in the seat heater but I'll admit I haven't done it yet because of how daunting any sort of repair looks to be.
https://www.youtube.com/watch?v=Z5qCOLv1Vg4.

If you search around a bit, it does seem to be a weak spot of the i3.

 

[Steve999]

Many seats (including mine) only the temperature sensor wire is broken, causing the seat heater to shut off after a minute or so. The video attached shows how to repair it in 30 minutes ... There's a bunch of other good repairs on the channel too. Mine has worked great after the repair + adj setpoint temp in bimmercode to my liking.

https://www.youtube.com/watch?v=K8UfK5-itZk

 

[rtanov]

I had a similar problem caused by broken temperature sensor wire. Ended up replacing the seat cushion (heater is integrated in it), but the broken wire could be repaired ... maybe. Here is my post about this: https://www.mybmwi3.com/forum/viewtopic.php?f=10&t=16597&p=66599#p66599

 

[Arm]

It's a nightmare to repair no matter what approach you take. Best to have the dealer do it.

 

[Obioban]

Many seats (including mine) only the temperature sensor wire is broken, causing the seat heater to shut off after a minute or so. The video attached shows how to repair it in 30 minutes ... There's a bunch of other good repairs on the channel too. Mine has worked great after the repair + adj setpoint temp in bimmercode to my liking.

https://www.youtube.com/watch?v=K8UfK5-itZk

That looks like exactly what I'll do.

Thanks!