[alackofspeed]

Hi all,

I have a UK M340i G21, that came with the standard (sport) seats with manual adjustment (asides from bolsters and lumber). I have a pair of electric seats from an X3M, which are mechanically the same as those in the M340i with Msport seats. Incidentally, in case anyone is unaware / interested, the frames are the same on 3, 4, X3, X4, and M8. Presently I have the X3M covers and foam built on to my original G21 manual frames.

I've got all the wiring mapped out, but as the driver's seat has a control module for all seat functions, rather than being a dumb unit like the passenger electric seat, I need to program the car to make the driver's seat work correctly.

I'm wondering if anyone is able to steer me to the correct module to code and what the specific coding changes required are.

In terms of programming tools, I have Bimmerutility and Bimmercode - I'm presuming Bimmerutility has the necessary functionality, but I'm new to BMW coding, so I may well be wrong!

All advice gratefully received. Thanks.

[TheNine90]

You can add 459 to FA and code BDC and the seat module.

[alackofspeed]

Thanks for the reply TheNine90. I've now modified the wiring as required for the driver's SM2 module and added the module to the FA using Bimmer Utility.

Now I need to code the seat to suit my car. The seat came from a RHD X3M.

Do you by chance know how to obtain the correct coding for a RHD M340i, please?

[TheNine90]

The seat should be compatible with the G20. Coding normally should be ok.

[alackofspeed]

Originally Posted by TheNine90

The seat should be compatible with the G20. Coding normally should be ok.

Thanks. I have been able to access and code the seat module using Bimmer Utility, however, the issue I'm now having is getting the seat memory buttons to work. I can't see where in the BDC coding to add the extra LIN device, with the result that when the seat memory button is connected it affects the operation of other LIN devices. BDC is reporting the error that seat memory switch is an unexpected device.

Any assistance would be much appreciated.

[alackofspeed]

After lots of searching through the BDC I found the coding required.

Should anyone else embark on this journey, here is the information you'll need.

[Assassin]

Originally Posted by alackofspeed

After lots of searching through the BDC I found the coding required.

Should anyone else embark on this journey, here is the information you'll need.

Interesting move.... could you post pics of your new seats in situ?

[alackofspeed]

I only have this picture from when I first installed the X3M foam and covers on the original G21 manual seat frames.

edit - I don't know why the forum software has rotated the photo 90deg.

[Mr Fish]

Originally Posted by alackofspeed

I only have this picture from when I first installed the X3M foam and covers on the original G21 manual seat frames.

edit - I don't know why the forum software has rotated the photo 90deg.

Hi, I have a g20 with the standard electric sports seats. you mentioned swapping over the foam and seat covers to your old manual seats. I was wondering if I would be able to swap over the foam and covers from an x3 to my existing seats to avoid all the rewiring and coding. I'm assuming everything would still work on the seats, adjustment, bolsters, heating and memory? as I want to retain those functions. I'm guessing the m logo lighting and powered headrest wouldn't work. but that doesn't bother me as I would want the headrest in the lowest setting anyway.

do you reckon this would all work? and how did you swap over the foam and covers to your manual seats? or would it just be easier to fit the x3 seats as is and figure out the coding (I have no idea and never have coded my BMW before)

Many thanks

[alackofspeed]

Mr Fish It's very easy to swap the covers and foam, however, if you already have electric seats you can simply swap the seats as all the wiring (except the power for pin 11 - the m logo) will be present in your car.

I expect no coding will be required in your case too.

Where in the UK are you based? I'm in Dorset.

[Mr Fish]

Originally Posted by alackofspeed

Mr Fish It's very easy to swap the covers and foam, however, if you already have electric seats you can simply swap the seats as all the wiring (except the power for pin 11 - the m logo) will be present in your car.

I expect no coding will be required in your case too.

Where in the UK are you based? I'm in Dorset.

I've heard on other forums that swapping the seats directly over can cause the seat controls to be reversed or non functional and the fix is to use the command box from the old seats in the new seats. I might just try both and see what happens.

not too fused about the logo lighting up but do you think the headrest will be powered if I do a direct swap?

I'm based in Warminster/ London (dependant on my work)

[alackofspeed]

Originally Posted by Mr Fish

I've heard on other forums that swapping the seats directly over can cause the seat controls to be reversed or non functional and the fix is to use the command box from the old seats in the new seats. I might just try both and see what happens.

not too fused about the logo lighting up but do you think the headrest will be powered if I do a direct swap?

I'm based in Warminster/ London (dependant on my work)

I'm near Wimborne, so circa 45 miles away. I may be selling my X3M seats (and the car) if you're interested.

As for the SM2 modules / coding, were I in your position, if you buy X3M seats or MSport seats from another car, I'd try directly swapping the seats first. The passenger seat will work fine, and I would expect the driver's seat to work fine too. However, if you need any assistance with the coding I'm happy to help.

Edit - I've now sussed the headrest coding.

[Mr Fish]

so quick update.

The seats fitted and worked fine. all seat movement and memory functions worked perfectly. all but the heating on the drivers seat. worked fine on the passenger side, but the drivers, as soon as I press the button for heated seats it immediately turns itself back off.

I then tried swapping to the drivers module from my g20 seats. this stopped the electric headrest from working but everything else apart from the heated drivers seat worked. still having the same problem turning itself off.

Any advice on this would be appreciated as it is almost perfect. the heated seat is not something I'm willing to loose. does this sound like some sort of coding or incompatibility problem? or have I just got a bust drivers seat?

I've heard that the heater module is separate. can anyone confirm this? is it only on the passenger side? As I only swapped the drivers seat module and not the passenger module. seems weird if the heater module works on the passenger side and not the driver

if I cant resolve this problem I'm going to have to return the seats I have. and probably will admit defeat and stick with the original seats.

Many thanks

[alackofspeed]

I'm no expert on the coding side of things, but that's where I'd be looking first.

On the G20/1 the passenger electric seat movement is simplistic and there's no seat module, just a heated seat controller. The driver's seat has just a seat module that controls every function of the seat, Including the heating.

[Mr Fish]

do you reckon my local BMW dealership would be willing to look into it/ code the seats to the car for me to make the heating work. or are they likely to turn me away as its a modification I've done myself?

[alackofspeed]

I don't know what the response from BMW would be. If you fancy popping down to nr Wimborne, I can use my seat coding file on the seat module that came with your MSport seats and see if that works. The heating works fine on my X3M seats.

[Kevinsilva]

I am also planning on trying to swap my 23’ M340i front seats to G8x seats , But i watched a few videos and they say there is coding involved. Did you have to do coding or is it just plug and play. And if there is what coding app could i use.

[slim25073]

Hi, I retrofitted two memory seats to my21 bmw. I did the wiring, the problem I have is both seat modules are interfering with each other - SM2. Which ground pin do I need to add/remove so the get different addresses on diagnosing? The seats came from a G42 M240i.

[ilir]

Hi!

My car came with manually adustable seats (sportline) and i would like to retrofit electric adjustable seats.
What should be done?
Wiring, coding,…?

Many thanks in advance!

[hg_automotive]

Hi. I’ve just purchased some X3M seats. I’ve got a BMW M340i G20. Could you help fit and code these for me alackofspeed. I’m on IG as hg_automotive if easier. Really appreciate any help. Thank you

[hg_automotive]

Also did the wiring pins stay the same for the X3M and plug straight in to the existing G20 wiring plugs or did you have to get new ones? alackofspeed and slim25073 MrFisher