[MENAC3]

Went to turn on drivers side seat heater this morning & it shut off after being on for about 5 seconds. Its been happening ever since, every time I try to turn it on..

Any ideas?

[forza1976]

Dealer visit

[todrice915]

Did you figure out the issue?

[Lifted]

Did you pay your $18?

[ghstm2]

Originally Posted by Lifted

Did you pay your $18?

Lmfao!

[95wildtt]

Originally Posted by MENAC3

Went to turn on drivers side seat heater this morning & it shut off after being on for about 5 seconds. Its been happening ever since, every time I try to turn it on..

Any ideas?

What did the dealer do to fix yours?

Mine's doing the same thing... worked fine 3 days ago, but doesn't work today.
Haven't changed anything or done any coding, but I get an error that the control line is either shorted to ground or open when I scan with my Autel.

Thanks,
John

[keneke45]

Literally just ran into the same issue here. '20 X3MC

[jareedo]

same for my 20 X3MC - just as we are hitting winter in Scotland!

[kzg1969]

Originally Posted by jareedo

same for my 20 X3MC - just as we are hitting winter in Scotland!

Off you JC you go then....

[BuiltMyWay]

Mine too. Turns on for 5 seconds and then turns off. I noticed the bottom left side bolster get really hot a few times before it stopped working.

Any one fix it?

Mine is tuned so really don't want to take to dealer because they'll plug it in.

[95wildtt]

Update...

Did a bunch of investigation on this, downloaded info from TIS including schematics and de-bug procedures, and spent some time becoming familiar with the operation and circuitry.
It looks like they did a step change and rolled the once separate seat heater module (like in the back seats) into the seat module itself sometime in 2019, as there are differing schematics and descriptions from what is in my F98.
I used my VIN for the data, but the info is different than what's in my car.

Anyway, I bought a new seat module (latest revision with heating) and swapped it out.
Unfortunately, no luck as the problem still occurs, no different behavior at all.
As reported above, my Autel reports an open or shorted line in the seat, and the error remained with the new module as well.
I can clear the error, and it only comes back when the seat heater is activated.

I have a 2020, and it looks like everyone else on this thread does too.
Is there a problem with the seat (wiring or thermistors) in the 2020s, or is this a larger issue...??

I don't want to go the dealer route with my tune and custom coding in a few modules either, but think it's likely a seat problem.
I will stay with my car to be sure it's not connected to the matrix, and if they can't do anything without assimilating my car, I'll look at other options (not sure what??)

It's about $2500 for new cushion and back seat covers (I think the wiring is built into them).

Thanks,
John

[F97 Devin]

Hey guys I had this problem as well. 2020 with 36k miles.. happened around 20k.. I took it to the dealer under warranty and they diagnosed it as a bad heated seat pad. They showed me pictures and it looked almost like one side caught on fire, the cushion was black and charred in one section.

[95wildtt]

That’s what I’m thinking it must be…
I’m at 22k miles.
Seems like a common problem with the 2020 models.

Was it the bottom or back pad?

Thanks!!

[Eddie.gomezzz]

Originally Posted by BuiltMyWay

Mine too. Turns on for 5 seconds and then turns off. I noticed the bottom left side bolster get really hot a few times before it stopped working.

Any one fix it?

Mine is tuned so really don't want to take to dealer because they'll plug it in.

I second this^ mine was working for a bit and would get really hot in the left side and then stopped working after a week.

[95wildtt]

Was it the seat base or the back that got really hot??

[F97 Devin]

For mine, it was the bottom.

[Eddie.gomezzz]

Originally Posted by 95wildtt

Was it the seat base or the back that got really hot??

Seat base left side bolster

[95wildtt]

Thanks for the updates...

Starting to see a trend here, and I guess it makes sense since the left side of the seat gets the heaviest wear from getting in and out of the car all the time.
At least on the NA models.

Almost feels like it should be a recall of some type...???

Update: bought the parts (cushion and heat pad) and will do this repair myself... let you know how it goes.

[Shogun1122]

Add another one to the list. 2020 X3M driver side seat heater with all the same issues. I just got it back from the dealership last week. Had to replace the heating element under warranty.

Clearly an issue.

[MadScientist1337]

Originally Posted by Lifted

Did you pay your $18?

Literally only opened this thread to see if someone had made this joke yet

Craziness.

[95wildtt]

Got the seat heater working again.
Just in time for -5F temps and -35F wind-chill

I hate taking my car to the dealer for service!!

Confirmed it was a burned wire in the left seat bolster near the back of the seat.
Very Minor damage to the inside leather cover, so I didn't replace it.
Photos included that show the problem.

It's not a bad job, but it does take a while.
Expect 4-5 hours if you take your time and are careful so as not to damage the leather cover of the seat or the very fragile wires in the heating pad.

Before proceeding, confirm this is your problem.
Remove the 4 bolts that hold the seat down, CAUTION: DON'T DISCONNECT THE YELLOW CABLE!! and tilt the seat backward.
The seat module is at the front very bottom of the base in a plastic honeycomb and the connectors face the back of the seat.

You don't need to remove the seat module to check the wiring...
From the bottom of the seat base look through the plastic honeycomb and find the connector in the 4th slot (#5 in the picture below) from the center console.
There is an empty slot, and that's normal, the one you want is the 4th slot over and it's a 4 pin connector with the cable going up to the bottom of the seat and to a black cable holder (it also has the large part number sticker on it).

Press in with a small screwdriver to release the lock (through the bottom of the honeycomb) from the seat control module, pull out the connector and measure the resistance across the 2 large contact pins.
Be sure you have the correct pins (brown and green/purple).
It should be around 2-3 ohms, if it's measuring open (no reading at all) that's your indication the wire in the heater pad has likely burned opened, like mine did.

If it measures 2-3 ohms, STOP HERE, this is not the problem with your seat.

I have attached the repair instructions out of TIS, follow these EXACTLY and you will have no issues...

NOTE: PAY VERY CLOSE ATTENTION TO HOW THE SEAT CUSION FITS IN THE SEAT FRAME AND TAKE LOTS OF PICTURES AS YOU GO!!

ALSO: DON'T HURRY, BE SURE YOU HAVE LOTS OF TIME TO CHECK YOUR WORK AND BE CAREFUL, THE SEAT COVER IS OVER $1000 IF YOU DAMAGE IT.

You will need the list of parts I have attached, it's only 3 different items (you will need 30 of the $.20 clamps), and I paid about $450 for all 3 parts... so is it worth a warranty repair or not, that's up to you.

It's not in the instructions, but you will be moving the 4 fans and cabling for them from your old foam cushion to the new foam cushion as the first step once you are ready for the new cushion, so be sure to note how the cabling is run on the bottom of the cushion.
It's very easy, but note that you do need to do it as the new cushion does not have any fans included with it...

You only get 1 shot with the adhesive applied to the heat pad, so be very sure you study the old cushion/heat pad before you start the new assembly process, and be sure you have moved the fans first, no going back.

You WILL NEED a set of ring nose pliers for the "clamps" and I spent the money on the BMW tool listed in the instructions (they worked great) so I very highly recommend them unless you are familiar with hog-rings and leather seats.
I was not...
The BMW part number for the pliers is: 83300492668 and they are about $50.

Additional Hint:
Measure the resistance across the brown and green/purple wire on the NEW pad BEFORE you install it to be sure it's 1-2 ohms.
You will need to short across the small connector at the front of the seat/pad where the knee bolster heater connects so you get a 1-2 ohm reading, otherwise it will show open.
When you re-connect the knee bolster in the final assembly step you will re-add about 1 ohm so then you should be back to measuring 2-3 ohms.
You don't want to put the whole seat back together just to find you have another bad pad and have to buy new parts and then start over

Additional Hint:
I left my meter connected to the brown and green/purple connection the whole time I was reassembling the seat so I knew if I damaged the very small wires while doing the re-build.
Fortunately, I did not but would be easy to do

Was it worth doing this myself vs having the dealership do it... to me, yes.
It was worth the $500 so I have piece of mind knowing nothing was forgotten or missed.
Your mileage may vary based on your mechanical skills and experience with working on your cars.
As far as the difficulty level, I would say if you feel comfortable changing the plugs in your car, you can do this.

I hate taking my car to the dealer for service!!

[Dasky_spas]

Originally Posted by 95wildtt

Got the seat heater working again.
Just in time for -5F temps and -35F wind-chill

I hate taking my car to the dealer for service!!

Confirmed it was a burned wire in the left seat bolster near the back of the seat.
Very Minor damage to the inside leather cover, so I didn't replace it.
Photos included that show the problem.

It's not a bad job, but it does take a while.
Expect 4-5 hours if you take your time and are careful so as not to damage the leather cover of the seat or the very fragile wires in the heating pad.

Before proceeding, confirm this is your problem.
Remove the 4 bolts that hold the seat down, CAUTION: DON'T DISCONNECT THE YELLOW CABLE!! and tilt the seat backward.
The seat module is at the front very bottom of the base in a plastic honeycomb and the connectors face the back of the seat.

You don't need to remove the seat module to check the wiring...
From the bottom of the seat base look through the plastic honeycomb and find the connector in the 4th slot (#5 in the picture below) from the center console.
There is an empty slot, and that's normal, the one you want is the 4th slot over and it's a 4 pin connector with the cable going up to the bottom of the seat and to a black cable holder (it also has the large part number sticker on it).

Press in with a small screwdriver to release the lock (through the bottom of the honeycomb) from the seat control module, pull out the connector and measure the resistance across the 2 large contact pins.
Be sure you have the correct pins (brown and green/purple).
It should be around 2-3 ohms, if it's measuring open (no reading at all) that's your indication the wire in the heater pad has likely burned opened, like mine did.

If it measures 2-3 ohms, STOP HERE, this is not the problem with your seat.

I have attached the repair instructions out of TIS, follow these EXACTLY and you will have no issues...

NOTE: PAY VERY CLOSE ATTENTION TO HOW THE SEAT CUSION FITS IN THE SEAT FRAME AND TAKE LOTS OF PICTURES AS YOU GO!!

ALSO: DON'T HURRY, BE SURE YOU HAVE LOTS OF TIME TO CHECK YOUR WORK AND BE CAREFUL, THE SEAT COVER IS OVER $1000 IF YOU DAMAGE IT.

You will need the list of parts I have attached, it's only 3 different items (you will need 30 of the $.20 clamps), and I paid about $450 for all 3 parts... so is it worth a warranty repair or not, that's up to you.

It's not in the instructions, but you will be moving the 4 fans and cabling for them from your old foam cushion to the new foam cushion as the first step once you are ready for the new cushion, so be sure to note how the cabling is run on the bottom of the cushion.
It's very easy, but note that you do need to do it as the new cushion does not have any fans included with it...

You only get 1 shot with the adhesive applied to the heat pad, so be very sure you study the old cushion/heat pad before you start the new assembly process, and be sure you have moved the fans first, no going back.

You WILL NEED a set of ring nose pliers for the "clamps" and I spent the money on the BMW tool listed in the instructions (they worked great) so I very highly recommend them unless you are familiar with hog-rings and leather seats.
I was not...
The BMW part number for the pliers is: 83300492668 and they are about $50.

Additional Hint:
Measure the resistance across the brown and green/purple wire on the NEW pad BEFORE you install it to be sure it's 1-2 ohms.
You will need to short across the small connector at the front of the seat/pad where the knee bolster heater connects so you get a 1-2 ohm reading, otherwise it will show open.
When you re-connect the knee bolster in the final assembly step you will re-add about 1 ohm so then you should be back to measuring 2-3 ohms.
You don't want to put the whole seat back together just to find you have another bad pad and have to buy new parts and then start over

Additional Hint:
I left my meter connected to the brown and green/purple connection the whole time I was reassembling the seat so I knew if I damaged the very small wires while doing the re-build.
Fortunately, I did not but would be easy to do

Was it worth doing this myself vs having the dealership do it... to me, yes.
It was worth the $500 so I have piece of mind knowing nothing was forgotten or missed.
Your mileage may vary based on your mechanical skills and experience with working on your cars.
As far as the difficulty level, I would say if you feel comfortable changing the plugs in your car, you can do this.

I hate taking my car to the dealer for service!!

I think it's worth saying- thank you. We appreciate taking the time to share all this.