NoQuarter

- Regular backrest adjustment has a single motor in each seat backrest. The left/right side is connected via a cable to the single motor so that both sides move exactly the same.

- So the Active Backrest has the 2 motors so they can operate the left/right backrest independently. These motors are more powerful and function faster. They also have position sensors so the wire harness has a LOT more connections.

- Moving the motors and the wire harness from the old seats to the new seats will be required. I don't know what to expect to be able to move the harness. I suspect it is all integrated into the existing seat harness and you won't be able to just take the backrest portion of the harness very easily.

- Plan on taking the seats completely out of the car. The leather is actually pretty easy to take off. You just cut off the "hog-rings" and the leather starts to unhook and just fold it towards the front. there will be some rings that are harder to reach but nothing unlike any seat cover project.

- Putting the leather back does not require any stretching or anything like that. Just hook the bits back where they belong. Be sure you already have on-hand a set of hog-ring pliers and bag of hog-rings. Easy to find on Ebay for about $10.

I would be glad to speak with you on the phone if you like. I am in the US EST time zone.

AI001

NoQuarter, much appreciated for your answer. I can see harness has to be custom made to work properly, quite hassling job. Thanks for your offer to speak this up. Let me secure the deal on the seats first before I dig deep on this.

Thanks again.

regards,
Afsar

NoQuarter

Did some work on my seats and snapped a few pics of the motors and the module installed.

Tygran

Hi All,
Can someone please tell me what's the part number for the buttons with DTC,ACTIVE SEATS AND HEATED SEATS,
I am currently trying to order from the BMW dealer but they unable to help me unless I'll give them part number for the correct part. Can someone help/advise alternatively is anyone got any other ideas from where can I get
DTC, Active seats and Heated seats buttons. (picture attached)


I have 535 with M5 seats with the following buttons:
tyre tread
Active seats
Heated seats


Thank you in advance

paulie

The active backrest is option S4MFA. So check the link below and based on your options pick one of the four.

Right side buttons:
RealOEM.com - Online BMW Parts Catalog


Left side buttons:
RealOEM.com - Online BMW Parts Catalog

Tygran

Paulie,


Thank you for the reply.


I am a bit confused now. The website you gave me. I am not sure which switch block would have the correct buttons:




( DTC, active backrest and heated seats,) - would you be able to tell me exactly part number I have 09 plate 535 diesel.


Your help would be much appreciated.

txag_530i

I'd recommend searching eBay for the correct switch.

Alternatively, go to etk.cc and enter in the last 7-digits of the car's VIN. Select 61 and scroll down until you see the center console switch. You can select the options that you want and the site will help you get the correct part number.

JuniorB

HI,I have a question if anyone's out there,I did a complete comfort seat retro in my car that is non sport,this was a plug and play,everything works mint. The only thing I found and can't find is what does the small yellow plug go to? I see the extra wiring in cars or SUVs with sport package. I'm wondering if that is for the active seat,or sport mode? My original seat was full power,heated.the comforts seats are out of a 550 sport,Hans the yellow plug. Anyone have thoughts that can confirm this? Thanks a bunch,and nice retro,I've read these seats are a mother to install in a car with no heat and limited power.

Glaede

Hi NoQuarter,

First, sorry for bringing up such an old topic, but couldn't find much help on this 4MF retrofit anywhere. Long story short, a couple of weeks ago, I bought a car with retrofitted comfort seats with 4MF, However, the PO, didn't complete the retrofit, which means that all functions except the active backrest and width adjustment works. Now, I would like to get it fully operating. I don't have the center switch panel with the active backrest buttons yet. It's crazy expensive!

So, what I would like, is just to make the adjustment buttons on the side of the seat work for a start and then eventually invest in the correct switch panel. Do you know if this is possible? As of now, when I click one of the round buttons all I hear is a clicking noise from a relay, but nothing happens. This "clicking" appeared after coding $456 to my VO. I forgot to code 4MF unfortunately (will do soon).

Thanks in advance! And thanks for a great write-up!

Kind regards,
Søren, Denmark.

NoQuarter

Awesome to see old projects ping me again!

As I read through the earlier posts, I noticed I mentioned that the new seat motors seemed to work OK without the new switch.

By OK I mean the traditional adjustment using the button on the side of seat would change the sides in and out but the automatic part would not work.

Whatever sound you are hearing in the seat, it is not a relay sound. There is nothing like that in the seat. The fact that it started after coding $456 is a sign that it is now trying to work but I don't know what the clicking is unless it is coming from under the seat and not the back.


You didn't mention if both seats behave the exact same way?


If the option was never coded, I suspect the proper wiring was not done either. Sounds like somebody bought some cool seats, bolted them in, and was disappointed when it didn't work right away.

The only way those seats are going to work is if they were properly wired into the PT-can and K-can network. If you unbolt the seat rails, tip the seat back and look under the seat where the wires and controllers are, you might be able to see where a home-made cable was added to wire in the network.

Good luck!