[bake]

Have the opportunity to swap my rear seats for the split folding seats. The rear seat is also heated and my car wasn't spec'd with rear heated seats. Will this be as easy as finding a tucked connector for the heating elements and then replacing the rear center console with a version with the rear seat heater buttons and plugging those in to a tucked connector? Or will those connectors not even be present??

[ezaircon4jc]

Originally Posted by bake

Have the opportunity to swap my rear seats for the split folding seats. The rear seat is also heated and my car wasn't spec'd with rear heated seats. Will this be as easy as finding a tucked connector for the heating elements and the man replacing the rear center console with a version with the rear seat heater buttons and plugging those in to a tucked connector? Or will those connectors not even be present??

No. You will need wiring harness(es), switches and probably more miscellaneous stuff. Add coding after that.

[M_Bimmer]

To the OP, there are two versions of the rear heated seat "buttons"....

1. Embedded in the 4-zone Rear Control Unit
2. Two Buttons under the rear center vent (pictured below)

#2 would be the easiest to MOD for your car, but still would require you to run wires:
- For the Buttons:
- - Power from JBE, Fuse F31, to rear of center console to both switches
- - K-LIN from JBE to rear of center console to both switches

- For the Heat Modules (under the seat cushion)
- - Power from rear fuse box, F188, to rear driver's side module
- - Power from rear fuse box, F187, to rear passenger's side module
- - K-LIN from buttons to both modules

You'd need to find a rear vent trim that has the two holes for the heat switches, and then switches.

You could do this at a later time after you've installed your split rear seat...

[bake]

Originally Posted by M_Bimmer

To the OP, there are two versions of the rear heated seat "buttons"....

1. Embedded in the 4-zone Rear Control Unit
2. Two Buttons under the rear center vent (pictured below)

#2 would be the easiest to MOD for your car, but still would require you to run wires:
- For the Buttons:
- - Power from JBE, Fuse F31, to rear of center console to both switches
- - K-LIN from JBE to rear of center console to both switches

- For the Heat Modules (under the seat cushion)
- - Power from rear fuse box, F188, to rear driver's side module
- - Power from rear fuse box, F187, to rear passenger's side module
- - K-LIN from buttons to both modules

You'd need to find a rear vent trim that has the two holes for the heat switches, and then switches.

You could do this at a later time after you've installed your split rear seat...

Thanks for this info, it is extremely helpful. I think I will still go through with retrofitting the folding seats, but probably won't bother with getting the heated seats functional. At least not at this time. If COVID continues to drag on into the summer, maybe I'll decide to take on that project, but I have enough going on right now.

[furkan24]

Originally Posted by M_Bimmer

To the OP, there are two versions of the rear heated seat "buttons"....

1. Embedded in the 4-zone Rear Control Unit
2. Two Buttons under the rear center vent (pictured below)

#2 would be the easiest to MOD for your car, but still would require you to run wires:
- For the Buttons:
- - Power from JBE, Fuse F31, to rear of center console to both switches
- - K-LIN from JBE to rear of center console to both switches

- For the Heat Modules (under the seat cushion)
- - Power from rear fuse box, F188, to rear driver's side module
- - Power from rear fuse box, F187, to rear passenger's side module
- - K-LIN from buttons to both modules

You'd need to find a rear vent trim that has the two holes for the heat switches, and then switches.

You could do this at a later time after you've installed your split rear seat...

Hello. I have 4-zone Rear Control Unit. I need wiring diagram. Please help me. Thanks

[M_Bimmer]

furkan24 mind sharing your F10 manufacturing date? Wiring may depend on it.

[furkan24]

My car 2010. . Power and ground wire okay. Rear fuse 187 & 188 power . But I don't know where the 2 yellow and 3 brown cables will be connected.

[furkan24]

https://files.fm/u/kdznr82mgf
https://files.fm/u/prsk98js6a

[M_Bimmer]

Hard to tell what that wire loom is coming from....

Here is the 1st schematic....and if you need more info on this module, let me know. Rear Seat Heater Module will be provided in the next post.

[M_Bimmer]

Rear seat heater wiring for the F10.

[McSpeedy]

M_Bimmer

Thank you for the very helpful posts and info above. I'm in the middle of a retrofit on my 750li F02 and hoping the same/similar applies as the F10, given the two share so much in common.

I have to go with option #1 from above, i.e., Embedded in the 4-zone Rear Control Unit and need additional help.

I have already installed the new rear climate control unit with heated seat buttons for driver/passenger sides.

I'm *assuming* the wiring loom from rear climate control to JBE is good, as the seat heat buttons are illuminated when lights are on.

I've installed the new rear seat back and bench, and the wiring and seat modules match the schematics you posted on 05-16-2024, which is encouraging.

I've found homes for the grounds, and run the two power lines to fuses 187 and 188 in the trunk.

I need help in running the two yellow lines (K LIN 6) up to the JBE, I think? I'm guessing they will go into the harness connector that runs from the rear to the JBE, but I don't know into which pins/positions.

I've already added code 496 to the vehicle's FA/VO, and I coded to module FKA (rear climate control), FRM, IHKA, and SM (seats) but so far I've can't get the buttons to "turn on." I don't know if this is because I haven't run the yellow wires up the K LIN to JBE, or something else.

Anyway--seems like I'm close to the finish line and just need some help to get across. Any advice or guidance you could offer would be greatly appreciated.

Thanks!

[M_Bimmer]

Originally Posted by McSpeedy

M_Bimmer

Thank you for the very helpful posts and info above. I'm in the middle of a retrofit on my 750li F02 and hoping the same/similar applies as the F10, given the two share so much in common.

I have to go with option #1 from above, i.e., Embedded in the 4-zone Rear Control Unit and need additional help.

I have already installed the new rear climate control unit with heated seat buttons for driver/passenger sides.

I'm *assuming* the wiring loom from rear climate control to JBE is good, as the seat heat buttons are illuminated when lights are on.

I've installed the new rear seat back and bench, and the wiring and seat modules match the schematics you posted on 05-16-2024, which is encouraging.

I've found homes for the grounds, and run the two power lines to fuses 187 and 188 in the trunk.

I need help in running the two yellow lines (K LIN 6) up to the JBE, I think? I'm guessing they will go into the harness connector that runs from the rear to the JBE, but I don't know into which pins/positions.

I've already added code 496 to the vehicle's FA/VO, and I coded to module FKA (rear climate control), FRM, IHKA, and SM (seats) but so far I've can't get the buttons to "turn on." I don't know if this is because I haven't run the yellow wires up the K LIN to JBE, or something else.

Anyway--seems like I'm close to the finish line and just need some help to get across. Any advice or guidance you could offer would be greatly appreciated.

Thanks!

I'm impressed. I'm not sure I've seen a whole lot of Mod's by that many F02 owners.

I need to dig into the F02 schematics (as my F02 already has 4-zone)...to ensure that the F02 is the same as the F10.

I'm not sure if I caught if your F02 is pre-LCI or LCI, so if you provide the MFG date on the VIN sticker on the B-Pillar, I can verify that I reference the correct schematics in TIS.

BTW, your 4-zone rear unit (HKA A131) has a CAN bus interface...and you make no mention on it's connection, and while it has a LIN bus connection too, it needs the CAN bus connection to the ZGM (A51), Central Gateway Module.

[McSpeedy]

M_Bimmer

Thank you for the lightning fast reply! Much appreciated.

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

Regarding the 4-zone rear unit (HKA A131) CAN bus interface... I need your help to provide more information.

My F02 was built with 4-zone rear, but no rear heated seats. I didn't change any wiring from the rear climate or harness up to the JBE.

I bought a used "rear heated seats" wiring set off of eBay, and I was able to separate the set into two different wiring harnesses:

1) The first was the wiring harness bits going from the rear seat control units to ground, power, and yellow wires, etc. This is the harness I mentioned in my previous post, i.e., I've plugged into the rear seat control unit, routed the grounds, routed the power to fuses 187 and 188, with yellow wires currently awaiting a home.

2) The second harness I recognized as being the one that runs to the rear climate control, cigarette ports, etc. I compared the wires in the plug for climate against the wires/plug I already had, and they were the same. There was one difference in the location of one wire, which I de-pinned and moved on my original harness to match the donor harness, and left the original harness in place.

I really, really, really hope that's OK--as it would be quite the effort to pull the center console, etc. out to run the new harness... and I know from experience, as I just did an interior swap from black leather to saddle brown leather. (Note: no new features introduced with new interior with the exception of retrofitting rear heated seats)

I hope this information above is helpful, please let me know if I may provide more. In particular I'd like to understand more about the CAN bus interface and what I may need to do there.

Thanks again!

[Boomer73]

I also have a 2015 F02 and would like to do this rear seat heat mod. I signed up to bimmerpost again (after a loooong time) just for this thread.

McSpeedy, you need to make a video on this mod.

[McSpeedy]

M_Bimmer

I now understand your comment about CAN lines running from climate to central gateway module. I will pull unit to inspect connector/wires and confirm, but I'm currently confident that both K_CAN_H and K_CAN_L will be present.

Assuming that's correct, and if I'm reading the diagram correctly, those two lines go to central gateway module (A51) and then out as K_CAN2_H and K_CAN2_L from central gateway to junction box (Z1).

If both statements above are correct, then I think that leaves running the two yellow wires (K_LIN_6) to the junction box. This leaves me with two questions.

1. I would presume the two yellow lines (K_LIN_6) would be distinct for passenger and driver seats. If so, shouldn't these have unique names, e.g., K_LIN_6 and K_LIN_7? The diagram currently shows these with same name and going into only one pin/position in junction box. Note, I was expecting two, i.e., one for each K_LIN.

2. Assuming that's correct, into which pins/ports of junction box (Z1) will said K_LIN need to insert?

Also, I'm assuming that if I mix these lines up, then one button could activate the other seat, e.g., driver button activates heat on passenger seat, etc. Not the end of the world, per se, and an easy correction.

Please let me know if I'm interpreting this information correctly and, if you're able, please let me know your thoughts about my two questions above.

Many thanks again in advance for any help you can provide. Cheers.

[McSpeedy]

M_Bimmer

I've confirmed the K_CAN_H and K_CAN_L lines are in place, per the attached photos.

In the first photo, you'll see positions 1-9. K_CAN_H and K_CAN_L are in positions 3 and 4, respectively.

In the second photo, you'll see positions 10-18. You can see that I moved TEMP_FHR from position 10 to position 18 to *match* the donor wiring harness. This was the wire I mentioned in my original post, and I changed this to *match* the donor harness. My mistake.

In the third photo, although blurry, you'll see I moved TEMP_FHR back to position 10 to match your wiring diagram. So, all good now and back to how the wires originally were.

Positions 17 and 18 are empty, which also aligns with your wiring diagram.

[McSpeedy]

Correcting issue adding photos

[M_Bimmer]

Originally Posted by McSpeedy

1) The first was the wiring harness bits going from the rear seat control units to ground, power, and yellow wires, etc. This is the harness I mentioned in my previous post, i.e., I've plugged into the rear seat control unit, routed the grounds, routed the power to fuses 187 and 188, with yellow wires currently awaiting a home.

2) The second harness I recognized as being the one that runs to the rear climate control, cigarette ports, etc. I compared the wires in the plug for climate against the wires/plug I already had, and they were the same. There was one difference in the location of one wire, which I de-pinned and moved on my original harness to match the donor harness, and left the original harness in place.

1. The LIN Bus wires (K_Line_6), 1 each, from each rear seat controller, runs along the right side of the vehicle up to a wiring node referenced as X227*1B, but really can be directly connected to the JBE A34*1B, Pin 9.

2. I'm not sure you should have a LIN Bus wire running from your center console to the JBE, unless your seat heater switches are external to the rear HVAC controller (I thought your HKA controller had heated seat buttons integrated into the controller itself)

The JBE installed in the vehicle must support rear seat heating, and I would NOT assume that your original JBE can just be FDL coded to "turn-on" rear heated seating if it did not come from the factory as such.

The one thing I'm not following is your need to relocate your wire for the rear right seat floor heater temp sensor on your HKA controller connector. Could you maybe provide a photo of your rear HKA unit?

[M_Bimmer]

McSpeedy , I can also take a picture of the connector on the HKA unit (rear HVAC 4-zone controller) tomorrow evening and post it to ensure that your wires are correctly pinned out with right colored wires.....if that would help.

[McSpeedy]

M_Bimmer

Thanks again for your reply. Please note I posted a few follow up responses above, including three photos from the rear climate connector. I believe all the wires are present and in their correct pin position.

I'll check out RealOEM to investigate the JBE... that seems to be my last question, i.e., routing the yellow K_LIN_6 wires up to either X227*1B or the JBE A34*1B, pin 9.

I'll have to ensure I have the appropriate JBE hardware, as you suggest, and perhaps in doing so will understand how connecting both K_LIN_6 wires into pin 9 will work. I was expecting two pin positions, i.e., one for driver side K_LIN_6 and one for passenger side K_LIN_6. But I'll keep plugging along.

In the interim, please let me know if you can't see the three photos I posted, as that could save you some effort. Again, I think we're in good shape there and the wires/pins now match your wiring diagram.

Thanks again my friend.

[McSpeedy]

M_Bimmer

One more thought about the JBE... my car already has front heated seats, and I was able to retrofit a heated steering wheel.

Might this suggest the current JBE could handle rear heated seats?

I checked RealOEM and it looks like the only difference in the two JBE options, i.e., part numbers 61356992415 vs. 61356992414, is:

"For vehicles with Park Distance Control (PDC)"
If S508A=Yes then = 61356992415
If S508A=No then = 61356992414

Quick search shows that S508A=Yes is the self-parking feature, which my car doesn't have. But I do have PDC, 360 cameras, etc.

I didn't see any other difference between the two JBE units, i.e., re: seat heating functionality.

Let me know what you think--I'm going to try and run the lines in the interim.

Thanks again and cheers.

[M_Bimmer]

A quick note....you should try and look into the electrical harness that runs on the right side of the vehicle into the trunk area, and the rear seat upper right cushion, if removed, should get you easy access to the harness....look for a yellow wire, and if there, that should be the same LIN Bus wire to the JBE you need for the rear seat heater control units (I'm not sure what options you have on your vehicle, so it's no guarantee that there will a LIN Bus wire at this location).

Once you get your LIN Bus wire connected for your rear seat heater controllers, try and FDL code and let's see if your JBE takes the coding. Let's take it from there.

Cheers