[Boomer73]

Originally Posted by McSpeedy

M_Bimmer

My F02 is LCI, model year 2015 to be exact.

I bought a used "rear heated seats" wiring set off of eBay

Do you know what the part number for this wiring harness is? I don't see it in RealOEM but maybe I'm missing something obvious. Was what you bought off ebay a complete harness or was it cut from a larger harness?

[M_Bimmer]

Boomer73, there are 2 main wiring harnesses that run the inside of the F10, and depending on options installed, the ends of the main harness may run into the trunk and into the engine bay, and even to the rear or front bumper….but it is not the engine harness as this is yet another separate wiring harness. This harness will have both fuse boxes attached to it.

The other internal harness is the audio and that depends on the audio system installed.

The HVAC and seat heating wires are part of the larger chassis harness, and it is not sold separately, nor is it installed if the vehicle didn’t have the option installed from the factory.

You will need to build a point-to-point wiring harness (TIS can help with the needed info) and tie it into your primary chassis harness per the TIS schematic, or you can buy a complete harness from a dismantled vehicle, such as those found on eBay, but not all harnesses are the same, and deattach the needed wires from the donor harness and then install. Unfortunately eBay Sellers very rarely provide a VIN so you can decode for the factory options. If you cannot verify the installed options, do not buy a “used” wiring harness. Good chance it won’t have the needed wires (color coded) or the needed factory connectors…….and if you go this route, you should be comfortable reading schematics and comfortable with wiring installation.

Hope this answers your question.

[Boomer73]

Originally Posted by M_Bimmer

Boomer73, there are 2 main wiring harnesses that run the inside of the F10, and depending on options installed, the ends of the main harness may run into the trunk and into the engine bay, and even to the rear or front bumper….but it is not the engine harness as this is yet another separate wiring harness. This harness will have both fuse boxes attached to it.

The other internal harness is the audio and that depends on the audio system installed.

The HVAC and seat heating wires are part of the larger chassis harness, and it is not sold separately, nor is it installed if the vehicle didn’t have the option installed from the factory.

You will need to build a point-to-point wiring harness (TIS can help with the needed info) and tie it into your primary chassis harness per the TIS schematic, or you can buy a complete harness from a dismantled vehicle, such as those found on eBay, but not all harnesses are the same, and deattach the needed wires from the donor harness and then install. Unfortunately eBay Sellers very rarely provide a VIN so you can decode for the factory options. If you cannot verify the installed options, do not buy a “used” wiring harness. Good chance it won’t have the needed wires (color coded) or the needed factory connectors…….and if you go this route, you should be comfortable reading schematics and comfortable with wiring installation.

Hope this answers your question.

Yes, it does. Like McSpeedy, I'm also working with an LCI F02 here (01/2015 build date) with 4-zone climate control, not an F10, but the same principles apply. What I'm trying to derive from yours and McSpeedy's info here is what components and processes are necessary to add heated rear seats to the F01/F02. From your statement above, it doesn't make any sense to me to get a wiring harness from a correctly optioned F02 and then try to pick out several wires from that harness - seems like both a long shot and harder than just making a dedicated harness from scratch given that there are only a few wires that need to be added here (if we know their origins and destinations).

There's a number of things I'm not clear on yet including where the wires from the JBE go, what the role of control module 61357490465 is, and whether or not FDL coding can turn on the seat heating function (assuming its all wired properly) if it wasn't include in VO from the factory.

[McSpeedy]

M_Bimmer

Thanks again for your help. I will look for the yellow LIN wire in the rear harness as soon as the weather clears up.

Question: Do you know which modules I'll need to FDL code to activate rear heated seats?

Note, I've already added option 496 to the FA/VO and I coded a couple of modules last week, per my initial post... but not sure if I missed a crucial module.

(This also assumes all hardware/labor are correct)

Thanks again, my friend

[McSpeedy]

Boomer73

I bought a used wiring harness set off of eBay for my retrofit project. It took a lot of searching to get what I needed. I'll try to share an example from an active auction to illustrate.

I think I paid around $50 for the lot, which included two (2) used wiring harnesses from an F10, i.e., one for front seats and the other for rear. I have an F02, but I know from experience they share some of the same DNA.

It took some time, but I was able to separate the mess of wires into two distinct harnesses.

1) The larger harness was for the front seats, and ran from the JBE through the center console all the way to the rear climate control plug. My F02 already has heated/cooled seats, so I compared the HVAC wires/plug and then did not need to use that harness. So I set it aside.

2) The small harness was just for the heated rear seats. This contained what I needed and is the "third" plug in the seat control module under the rear bench. This harness has two plugs, and each plug has a wire for ground, power, and the yellow LIN wire.

My F02 has a ground junction on the passenger side behind rear seat back, so I routed both grounds there. The power wires route through rear wall (follow wiring harness) and go to back side of rear fuse box in (I believe) positions 187 and 188. Please check the thread to be sure.

I'm working with @M_Bimmer now about the two yellow K_LIN wires... we believe they run up to central gateway, but possible I can just tap into existing K_LIN wire in my rear harness, if I can find it.

I'll keep you posted as I make progress. We just got hit with major snow storm so it's going to be a few days before I'm able to work on this.

Hope that helps, my friend. Cheers

[McSpeedy]

Boomer73

I couldn't find any active auctions on eBay, so here's a screen shot of what I bought for this project.

Hope this helps.

Cheers

[Boomer73]

Originally Posted by McSpeedy

Boomer73

I couldn't find any active auctions on eBay, so here's a screen shot of what I bought for this project.

Hope this helps.

Cheers

Interesting. So, this loom was taken out of a vehicle with the full electric adjustable rear seats - articulating, massage, ventilation...everything. That's why there's all the extra wire and why you don't need most of it.

If I understand you right, you're doing what I want to do - just add heated bench seats in place of the unheated basic bench seat that are activated via the factory rear climate controls. Is that right? This was the Luxury Seating Package option.

It seems to me like there should be:

1. a ground wire set up exactly as you have it,
2. a wire run from the JBE to the seat heating control module (is this 61357490465?)
3. wire(s) run from the seat heating module (SMSH) to the heating elements
3. a control/trigger wire to turn that power on when the heating button is pressed that runs from the rear console button to the JBE.

What is the role of the SMSH? Is it the same as part number 61357490465? Where is it located in cars that are equipped with rear seat heat?
Is there one of those control units each for passenger and driver side? What lets the computer know that that unit(s) exists in the vehicle? FDL coding? From reading the attached PDF it seems like the control modules are individually coded to identify which side they are on. How is that accomplished?

Attached is a PDF of what I have on this seat specific to the F01/F02. I believe I got this from TIS when I had a brief subscription. I would note that there seems to be an error in the explanation table. It seems the explanation for 6 and 8 are reversed.

[McSpeedy]

Boomer73

Yes, I am just retrofitting heated seats to my rear seats. No other changes.

You are mostly correct in how this should work. @M_Bimmer posted a wiring diagram that should answer your questions, i.e., it lays out the rear seat wiring config in detail. I've attached below.

The K_LIN, i.e., yellow wires) will come via JBE/central gateway and "tell" the rear seat modules what to do. Everything else you stated is correct in principle, i.e., each seat has a ground, a power, and a means to plug into the rear seat module (one for each side, driver and passenger), which in turn control the seat bench and seat backs.

I added the buttons for rear seat heating in my F02 to the 4-way climate control HVAC unit, i.e., I bought a used one and swapped them out. I've not had to change any wiring from that end, i.e., from the rear climate up to JBE. I believe everything is in place, per my pictures.

I'm currently working on my own and with M_Bimmer to resolve the K_LIN yellow wires, that's my last step. I'll keep folks posted.

The diagram below shows rear seat wiring quite neatly and should answer your questions.

Cheers

[Boomer73]

Originally Posted by McSpeedy

Boomer73

Yes, I am just retrofitting heated seats to my rear seats. No other changes.

You are mostly correct in how this should work. @M_Bimmer posted a wiring diagram that should answer your questions, i.e., it lays out the rear seat wiring config in detail. I've attached below.

The K_LIN, i.e., yellow wires) will come via JBE/central gateway and "tell" the rear seat modules what to do. Everything else you stated is correct in principle, i.e., each seat has a ground, a power, and a means to plug into the rear seat module (one for each side, driver and passenger), which in turn control the seat bench and seat backs.

I added the buttons for rear seat heating in my F02 to the 4-way climate control HVAC unit, i.e., I bought a used one and swapped them out. I've not had to change any wiring from that end, i.e., from the rear climate up to JBE. I believe everything is in place, per my pictures.

I'm currently working on my own and with M_Bimmer to resolve the K_LIN yellow wires, that's my last step. I'll keep folks posted.

The diagram below shows rear seat wiring quite neatly and should answer your questions.

Cheers

Except this is an F10 diagram, not an F01/F02 diagram, right? And while they may be similar nobody has confirmed they are identical, correct?

Is resolving the K_LIN wires a matter of identifying where they insert in the origin/destination plugs at the JBE and SMSH?

The SMSH/Seat Heating Module depicted in the diagram provided by M_Bimmer seems to have one less wiring inputs/outputs (10) than the module I could find for our cars (provision for 11). The module that I believe is the correct one for our cars (see attached) has receptacles for 3 plugs: two 3-wire plugs and one 5-wire plug. Is it obvious to you from the heated seat and wiring harness you have where the upper and lower seat plugs go into the SMSH and which one returns to the JBE?

When you installed your climate controls with seat heater buttons in the rear console, was it obvious to you that the LIN_Bus wires back to the JBE were already present in the center console harness, or did you have to add those?

EDIT: So it seems the SMSH unit I have is broken and missing a pin which was the source of my confusion. However my other questions still stand.

[McSpeedy]

Hi Boomer73

I believe the wiring diagrams are the same between F01/F02 and F10. I cannot confirm, per se, but if I get my rear seat heating working I will consider that a vote in that direction.

I haven't worked on the remaining LIN_6 wires yet due to weather, so I have no update there yet.

I can confirm, however, that the rear seat module is shared between F01/F02 and F10 per RealOEM. The current part number is 61357490465 and is shared across several models, including those above.

Yes, it is apparent which plugs go in which spot on the rear seat module. I believe between size/shape and color coding, BMW have done a good job to make this apparent when plugging the three connectors in.

The three plugs going into the rear seat module will be:

1. The plug from rear seat back cushion (i.e., to heating elements)
2. The plug from rear seat bench cushion (i.e., to heating elements)
3. The plug from JBE with grounds, power, and LIN wires

I hope this helps. Cheers

[McSpeedy]

M_Bimmer

I have some updates.

I was able to get under the dash and confirm the wiring up front matches your diagram, specifically:

1. Wires for K_CAN2_H and K_CAN2_L coming from the central gateway module are present on A34*2B in positions 1 and 2, respectively;
2. Position 9 on backside of junction box in A34*1B is the yellow wire for K_LIN.

(the second bullet includes the assumption that, because the wire is yellow, it is the same K_LIN as yellow K_LIN_6 further down the chain in the diagram)

I also took your suggestion and followed the wiring harness through the rear wall into the trunk and tapped into a "yellow" wire--again, in hopes this is all one large K_LIN system.

I was successful in tapping in the sense that car starts, no errors present, everything appears to be working as normal.

I was unsuccessful in that this did not have any apparent effect on the rear heated seats, i.e., they still don't function. Note, I did FA/VO coding a couple of weeks ago already.

So, I need some help--I'm out of ideas.

I do have one last straw to grab at from your diagram, i.e., below the K_LIN coming out of position 9 of A34*1B there appears to be a "junction" on the diagram in the notation of X227*1V. I did some Google searching and couldn't find anything on this.

My ask: Can you shed any light on what X227*1V is, e.g., what it is, where it's located, if I need to tap my K_LIN_6 wires into that, etc.

Any help would be greatly appreciated... it feels like I'm almost there.

Cheers

[M_Bimmer]

McSpeedy,

There is an FDL code to enable rear heated seats in the JBE...it is NOT included with 4-zone (you can see that some rear HKA's don't have rear heated seat buttons and additionally others don't have the cooling buttons - my F02 has both on the rear temperature controller). If you need help specifically on the FDL portion, reach out.

X227*1V location is provided in the 1st figure below.

K_LIN and K_LIN_6 are the same...but to be specific, K_LIN_6 is the yellow wires from each rear seat heat controller, and both left and right should tie together, and both should tap into the LIN Bus wire on the right side of a LHD F02 that goes to the JBE, which will need coded for rear seat heating.

If you describe what K_LIN is in your context, I'll update my response accordingly.

[McSpeedy]

M_Bimmer

Thanks again for the quick reply.

Ideally, I'd like to tap into X227*1V up front. It looks like I'll need to remove the passenger seat to pull the carpet back to access that junction. Does that sound correct to you?

Yes, I think I also need help with FDL coding. I used Esys to add option 496 to my FA/VO and coded/updated a few ECUS about two weeks ago. I won't rely on memory to say which, but I used good judgment. However I still have no success. So I think I do need help at this time, if you're able.

Thanks again and cheers.

[M_Bimmer]

Originally Posted by McSpeedy

Ideally, I'd like to tap into X227*1V up front. It looks like I'll need to remove the passenger seat to pull the carpet back to access that junction. Does that sound correct to you?

That passenger footwell location of X227*1V is in a very hard spot to get to, and would just use the junction box location. That location under the carpet will require you to peel the carpet from the right corner of the firewall, and peel back until you get to the wire harness "tube". Given that the carpet is one piece, and you can not really on get to the desired location unless the carpet is removed, which requires the air distribution box to be removed, which is real pain in the @ss.

Originally Posted by McSpeedy

Yes, I think I also need help with FDL coding. I used Esys to add option 496 to my FA/VO and coded/updated a few ECUS about two weeks ago. I won't rely on memory to say which, but I used good judgment. However I still have no success. So I think I do need help at this time, if you're able.

When added S486 to your VO list, did you notice if this required an update to the JBE? You should verify the following:
- 3050: sitzheizung_fond = aktiv

[McSpeedy]

Hi M_Bimmer

Thank you--the info on FDL coding the JBE was helpful. I got into Esys this morning and was able to update some settings under the JBE to activate rear heated seats, and now the control buttons are working. That's a major step forward!

The rear seat heating still isn't working, however, but I have an idea of what's left to do, i.e., moving the K_LIN connection.

The two yellow K_LIN_6 wires from the rear seats are currently tapped into some yellow wire in the trunk area near the fuse box. I'm going to undo that connection and move the two wires up to the front, i.e., to the K_LIN wire coming out of position 9 of the A34*1B.

I've attached a screen shot from ISTA+ that supports this change, i.e., rows 3 and 4 indicate the rear seat heating is missing the LIN component.

Note: You can disregard the other errors, they've been compiling as I've been working on this project. The only valid error I have to tackle next is for the recirculated-air-flap motor, which is a known issue.

The weather looks promising Sunday, so I'll try to tackle the wires then. I'll keep everyone posted and--hopefully--have some more positive news to share.

Thanks again--cheers.

[M_Bimmer]

Originally Posted by McSpeedy

Hi M_Bimmer
The two yellow K_LIN_6 wires from the rear seats are currently tapped into some yellow wire in the trunk area near the fuse box. I'm going to undo that connection and move the two wires up to the front, i.e., to the K_LIN wire coming out of position 9 of the A34*1B.

Hi McSpeedy , I've been trying to find what is connected to the LIN Bus wire that runs to the rear of the vehicle on the F02....and so far, I cannot find anything in TIS, but it's a lot to comb through too...so in order to get your system up and running without further delay, tie your rear seat module yellow wires together and to a much longer single wire to run it up to the JBE.

Hopefully you get closure on this ASAP.

Cheers

[Boomer73]

Originally Posted by McSpeedy

Hi Boomer73

I believe the wiring diagrams are the same between F01/F02 and F10. I cannot confirm, per se, but if I get my rear seat heating working I will consider that a vote in that direction.

I haven't worked on the remaining LIN_6 wires yet due to weather, so I have no update there yet.

I can confirm, however, that the rear seat module is shared between F01/F02 and F10 per RealOEM. The current part number is 61357490465 and is shared across several models, including those above.

Yes, it is apparent which plugs go in which spot on the rear seat module. I believe between size/shape and color coding, BMW have done a good job to make this apparent when plugging the three connectors in.

The three plugs going into the rear seat module will be:

1. The plug from rear seat back cushion (i.e., to heating elements)
2. The plug from rear seat bench cushion (i.e., to heating elements)
3. The plug from JBE with grounds, power, and LIN wires

I hope this helps. Cheers

That's very helpful, thank you. Can you share a picture of where the 61357490465 modules mount?

[McSpeedy]

Folks, great news--we have heated rear seats! Phew!

M_Bimmer Thank you very much--I couldn't have done it without your help here! Cheers, friend.

The final bit was the K_LIN_6 wiring. I ran both of the yellow K_LIN_6 wires from the seat connector under the carpet and along the passenger side up to the front. I had to remove the dash, etc. to get full access to the fuse box, which I pulled down to access A34*1B (connected to back of JBE, which is bolted on to fuse box).

I disconnected A34*1B and removed the connector cover to access the wires. I de-pinned position 9, i.e., K_LIN_6 and tapped into that. I just cut K_LIN_6 where I had a little slack, tied in the two yellow LIN wires from the rear, and re-soldered to the pin connector half of K_LIN_6. Not the OEM way, but it's tidy and secure.

I then wrapped that new junction in electrical tape, re-pinned K_LIN_6 into position 9 of A34*1B, put everything back together and... voila, heated rear seats. My wife already told me not to sell this car! Lol, if you knew my wife, you'd fully appreciate that milestone.

I had a couple of boo-boo's along the way, i.e., I'll need to replace a few plastic clips, screws, and other misc. casualties from working with rush on the trim, etc. But nothing major by any means. I'm also now an expert at removing the entire carpeting/liner from the trunk.

Hmm... speaking of which, I may upgrade the trunk to the "pass through" option as that was included with heated rear seats that I bought. Maybe in the spring?

Boomer73 I'll try to summarize what I did for the rear seats to help where I can. The first time was rough, but now that I know what needs done, it's actually not that terrible of a task. I'll also put together what I can about the heated steering wheel.

Question: Does your car have blind spot/lane departure warning? If so, the retrofit for heated steering wheel will be relatively straight forward.

[M_Bimmer]

McSpeedy, now you can FDL code (real easy with BimmerCode, but can be done with ESYS) a different temperature preset value for each of the three LED settings, and independently for the lower cushion versus the back cushion.

I set all three settings to their highest setting allowed temperature....partially because the highest setting wasn't hot enough (it also allows the seat to heat up much quicker), especially for the rear seats.

Additionally, depending on your i-drive version, you may be able to enable the seat heat adjustments to be controlled through i-drive (although this may not be as valuable for the rear seat occupants if you don't have RSE in your F02).

Reach out if you need help on FDL coding the seat temperatures.

[McSpeedy]

M_Bimmer

I will definitely take you up on that offer, I'd like to see what I can customize.

I connected my car to Esys yesterday to start poking around, and I encountered something strange.

I'm able to establish a connection, however Esys flashed a brief message to the effect that all VIN information was/would be wiped to ensure privacy... I had never seen that message before.

Once I loaded/saved the FA, read the ECUs, etc. and started looking at the CAFD files, e.g., the JBE, the detailed info that had been there before is now gone. Meaning, all of the folders are still present, but the labels describing what the contained were blank. I could still expand folders, etc. but I have no idea what I was looking at.

I'm going to attempt to update Esys tonight and try again---but in the interim, have you ever heard of this or know what may have happened?

Thanks

[Boomer73]

Originally Posted by McSpeedy

Folks, great news--we have heated rear seats! Phew!

M_Bimmer Thank you very much--I couldn't have done it without your help here! Cheers, friend.

The final bit was the K_LIN_6 wiring. I ran both of the yellow K_LIN_6 wires from the seat connector under the carpet and along the passenger side up to the front. I had to remove the dash, etc. to get full access to the fuse box, which I pulled down to access A34*1B (connected to back of JBE, which is bolted on to fuse box).

I disconnected A34*1B and removed the connector cover to access the wires. I de-pinned position 9, i.e., K_LIN_6 and tapped into that. I just cut K_LIN_6 where I had a little slack, tied in the two yellow LIN wires from the rear, and re-soldered to the pin connector half of K_LIN_6. Not the OEM way, but it's tidy and secure.

I then wrapped that new junction in electrical tape, re-pinned K_LIN_6 into position 9 of A34*1B, put everything back together and... voila, heated rear seats. My wife already told me not to sell this car! Lol, if you knew my wife, you'd fully appreciate that milestone.

I had a couple of boo-boo's along the way, i.e., I'll need to replace a few plastic clips, screws, and other misc. casualties from working with rush on the trim, etc. But nothing major by any means. I'm also now an expert at removing the entire carpeting/liner from the trunk.

Hmm... speaking of which, I may upgrade the trunk to the "pass through" option as that was included with heated rear seats that I bought. Maybe in the spring?

Boomer73 I'll try to summarize what I did for the rear seats to help where I can. The first time was rough, but now that I know what needs done, it's actually not that terrible of a task. I'll also put together what I can about the heated steering wheel.

Question: Does your car have blind spot/lane departure warning? If so, the retrofit for heated steering wheel will be relatively straight forward.

AWESOME NEWS MCSPEEDY!! Congrats!

I'm sure quite a number of people would like to do this mod and if you end up posting a how-to, it will likely become the definitive rear seat heat thread.

To answer your question, yes, my F02 has Blind Spot/Lane Departure.

-B