Modifying seat controls

[Greenfingers]

The cloth seats in my ex police G31 are okay, but along with the cloth trimmed door panels are a bit low rent.

I'm still using the F07, having just advertised it for sale (hope this cheeky link is allowed - https://www.ebay.co.uk/itm/144945418971 ) , so now is a good time to strip out and refit the G31.  I've already had the centre console apart and head unit out in preparation for the new Android screen that's on it's way from China and should provide a nice upgrade to the very basic idrive system. A set of used leather seats and door panels should be worth the investment, but now I'm wondering about compatibility:

My seats are the base spec, which includes the normal electric raise/lower/tilt base and reclining backrest, but they also have the round button providing 4 way lumber adjustment. Leather sports seats seem to be regularly available on eBay and would do fine, but of course they have different controls. I assume the standard base and backrest adjustments will be the same, but they also have bolster adjustment which would need to be functional. Has anyone here had a look at the wiring harness under their seats and do you think it would be viable to use the existing lumbar adjustment power supply for the bolster adjustment instead?

[Kopfjaeger]

Have you tried looking at the wiring diagrams for the seats? You can find them online, if you're lucky, or some other members may know.   If you've got ISTA, or similar software, you can find the wiring diagrams there? The extra functionality, for example, may require additional wiring between seats and the associated control module ( I'm guessing the FRM).  Adding the extra wiring, maybe fiddly...but I doubt you would need different connectors.  The other option is to get a seat wiring loom and retrofit that?

When I retrofitted wing mirror cameras to my F07, i just added the extra wires...all the plugs and sockets were good and empty apertures populated as per the wiring diagrams....As an engineer, you'll probably enjoy it?  The hard part maybe getting the correct colour coded cables, but if you're not fussy about that...straightforward?  You might need to code the option after upgrading the seats, as the VO for comfort and sport seats would be different.

Edited February 18, 2023 by Kopfjaeger
Typo

[Greenfingers]

Thanks, that does make sense. I don't have ISTA or Bimmercode - stupidly bought a 'Autophix 7910' recently and it doesn't do coding! But it's reassuring to hear that your car didn't throw a fit when you added some wires and I'm fine with doing a splice or two.

I've never looked at the underside of a modern BMW seat, but it sounds like they come with a module specific to the seat functionality. I'm hoping that the harness may be the same regardless of the seat options and might perhaps just plug in and work.

There's bound to be a solution, but I'll try unbolting a seat tomorrow and see what's there before buying replacements.

[Greenfingers]

A bit of research has revealed that there is more than just seat motor functionality to consider when replacing seats. The chances are that those on eBay have come from crashed cars and I had anticipated having to swap out the airbag modules, but what about seat belt pretensioners and active head restraints?

Maybe the parts could be salvaged from my outgoing seats, but this job is starting to look more complicated.

Anyway, I came across some very detailed and revealing information about the passive safety systems incorporated into the G30. It's worth a read if you are an owner, so I'll post it now as a separate topic.

 

[Matthew]

18 hours ago, Greenfingers said:

Thanks, that does make sense. I don't have ISTA or Bimmercode - stupidly bought a 'Autophix 7910' recently and it doesn't do coding! But it's reassuring to hear that your car didn't throw a fit when you added some wires and I'm fine with doing a splice or two.

I've never looked at the underside of a modern BMW seat, but it sounds like they come with a module specific to the seat functionality. I'm hoping that the harness may be the same regardless of the seat options and might perhaps just plug in and work.

There's bound to be a solution, but I'll try unbolting a seat tomorrow and see what's there before buying replacements.

There are numerous seat modules dependant on the type of seats and features fitted. The driver's and passenger seats have individual modules attached under each seat and the connect back to the Body Domain Controller (BDC) using the CAN bus so all connectivity from the seat motors, valve blocks and pumps is to the local seat module. (Just for info there is no FRM module on the Gxx series cars). If you can identify the modules fitted to your car, you can use Realoem to see if this module supports other features too.

Edited February 19, 2023 by Matthew

[Kopfjaeger]

Any second hand seats should have any safety related features checked and ideally replaced, if the donor vehicle has been involved in an accident. The seatbelt pre-tensioners are likely to be easier to replace than air bags fitted inside the seats.

The seat bolts should also be replaced with new, as I believe these are single use, stretch types, so shouldn't be reused.

[Greenfingers]

After unbolting and tipping back the driver's seat, I was confused by not finding any of the modules listed in Realoem. Here's a photo:-

Apart from the connector block for the yellow harness, the only thing resembling a control module is the block housing the switch controls.

Realoem indicates a large and a small module under both front seats and I couldn't find any. Eventually I realised that the large module is only fitted on seats with memory function, because cars with driver seat only memory have 1 and cars with both seats memory have 2. The smaller module appears to be only applicable to seat heating. I have neither the memory or heat functions, which I think explains why I don't have any modules under the seat.

Therefore, am I right in thinking that all seat variants have self contained functionality and utilise a common wiring harness and furthermore, does it follow that if you add memory function seats along with the relevant door cards and heated seats along with the correct dashboard panel, the existing wiring harness would provide full functionality?

I've never done coding, but presumably something like Bimmercode could instruct the BDC?  to recognise the new components?

 

[Matthew]

12 hours ago, Greenfingers said:

After unbolting and tipping back the driver's seat, I was confused by not finding any of the modules listed in Realoem. Here's a photo:-

 

Apart from the connector block for the yellow harness, the only thing resembling a control module is the block housing the switch controls.

Realoem indicates a large and a small module under both front seats and I couldn't find any. Eventually I realised that the large module is only fitted on seats with memory function, because cars with driver seat only memory have 1 and cars with both seats memory have 2. The smaller module appears to be only applicable to seat heating. I have neither the memory or heat functions, which I think explains why I don't have any modules under the seat.

Therefore, am I right in thinking that all seat variants have self contained functionality and utilise a common wiring harness and furthermore, does it follow that if you add memory function seats along with the relevant door cards and heated seats along with the correct dashboard panel, the existing wiring harness would provide full functionality?

I've never done coding, but presumably something like Bimmercode could instruct the BDC?  to recognise the new components?

 

The wiring for the basic seat with part electric adjustment is quite different from the fully electric seats with memory - all the way back to the BDC so it won't be wiring plug and play and a bunch of new wires are likely needed between the seat connector and the BDC. Add to that the emergency service car's unique wiring. I've never used Bimmercode, only ESYS so can't say either way for coding. The VO (Vehicle Order) will need to be changed to add the code for the type of seat you’re adding plus it’s features and there will have to be individual module coding to make the system work.

Edited February 21, 2023 by Matthew

[Greenfingers]

Okay, thanks for the explanation. In that case, the solution could be to get manual sliding sports seats and then either rearrange the pins in the connector, or adapt the wiring so the lumbar adjustment wires operate the bolsters instead.

I'm starting to wonder whether this would be a worthwhile upgrade from the existing seats, bearing in mind the caveats of buying used replacements which may have damage or blown airbags and head restraints.

[Matthew]

1 hour ago, Greenfingers said:

Okay, thanks for the explanation. In that case, the solution could be to get manual sliding sports seats and then either rearrange the pins in the connector, or adapt the wiring so the lumbar adjustment wires operate the bolsters instead.

I'm starting to wonder whether this would be a worthwhile upgrade from the existing seats, bearing in mind the caveats of buying used replacements which may have damage or blown airbags and head restraints.

Blown or damaged head restraints or airbags will be very evident when you look at the replacements. 
 

Also, I don’t think lumbar support was standard so you’ll need to find seats with that option. 

Edited February 21, 2023 by Matthew

[Greenfingers]

14 minutes ago, Matthew said:

Blown or damaged head restraints or airbags will be very evident when you look at the replacements. 
 

Also, I don’t think lumbar support was standard so you’ll need to find seats with that option. 

I imagine vehicle dismantlers are pretty savvy about disguising this sort of thing. It looks like you just need to remove the blown charge bolt from the head restraint to be able to push the headrest back into place and I'm guessing you could hide a blown airbag by removing it and closing the side of the seat.

Re the lumbar adjustment - the cloth police seats have this feature (and are actually quite comfy), so I was considering using that circuitry to power the bolster adjustment on the replacement seats.

[analityk2]

On 21/02/2023 at 09:50, Greenfingers said:

Okay, thanks for the explanation. In that case, the solution could be to get manual sliding sports seats and then either rearrange the pins in the connector, or adapt the wiring so the lumbar adjustment wires operate the bolsters instead.

I'm starting to wonder whether this would be a worthwhile upgrade from the existing seats, bearing in mind the caveats of buying used replacements which may have damage or blown airbags and head restraints.

Hi, which seats did you finally fit?

I also have ex police g30 with exactly same seats. Would fully electric seats (electric back and forward ) work on my wiring (manual back and forward) ?

I don't want to loose lumbar support option so looking for leather sport seats with that feature but would be nice have full electric if not additional wiring involves. Thanks 

[duncan-uk]

On 21/02/2023 at 11:17, Greenfingers said:

I imagine vehicle dismantlers are pretty savvy about disguising this sort of thing. It looks like you just need to remove the blown charge bolt from the head restraint to be able to push the headrest back into place and I'm guessing you could hide a blown airbag by removing it and closing the side of the seat.

I’m not sure they’d bother. It’s quite regulated now as I understand it and the car would throw up all sorts of codes you couldn’t clear.