Looking for some lessons learned and advice on this issue. I've looked on this, and Bimmerforums but can't find anything conclusive that will point me in the right direction.
The seats that I picked up from fellow board member 5S0NG are finally reupholstered. Aside from the fact that this took way, way too long, I think I want to move into the car for good they are so comfortable. New foam on the bottoms, new leather bolsters and headrests, and new Uberkaro fabric from member Bimmerbreaker (ASC Fabrics) for the center sections.
The upholstery guy built up the center sections with extra batting which makes them super comfortable, I think the combo of leather and uberkaro looks great (my own version of the $4000 Porsche 911 "heritage" upholstery option), and man they are comfortable with the new lower foam and extra padding in the centers. Unfortunately, the leather bunches up a bit when the seat back articulates forward, and they could be a bit tighter in other places, but after 2 years I was just happy to have them back. The pic below is with the all functions of the seats adjusted full forward to help get to the rear bolts. The headrest, on the other hand, are way nicer than OE with new leather and electric adjustability. Super happy overall. I'd gotten used to the insanely poor shape my OE seats were in and can't believe how nice these feel. It really helps that the upper back is adjustable and the upholsterer put the steps in the uberkaro in the right places for support.
Heat is very nice too and works great. My OE seats didn't have heat, but I got the correct control panel off of ebay and the guy steamed pads off the old foam off and glued them onto the new foam.
Eventually my plan is to put the uberkaro in the centers of the rear seats too.
The swap was easy, except for the fact that I'm left with an airbag light on the dash which was initially for the seat belt tensioners and the Seat Occupancy detector. The tensioner codes reset with the foxwell, but the occupancy detector has not. After digging into it more today, it looks like the new seats don't have the same occupancy detector as the old ones. I believe the new ones are post LCI comfort seats, which on RealOEM show having the same basic mat and little box under the seat, but in reality the new ones I put in don't have this small box anywhere that I can see under the seat. So, I'm left to assume that 1) the mat has failed or 2) the module is looking for the small box and not finding it.
Old Seat with the plug to the small (black) box that is labeled "occupancy sensor " in real oem circled:
New seat with the spot circled where it should snap into, but simply isn't there. The arrows in both pics point to connectors that run into the seat, presumably to the occupancy detector mat and heat mat. They are unfortunately different between the old and new seats, making it impossible to simply plug the little box into the new seat wires:
If whatever module that controls this stuff is looking for this little box and cant find it, perhaps I could swap or splice in the one in from my old seat and install a resistor that is available on ebay to clear the code and airbag light by fooling the car into thinking the seat is occupied. Or, I read on the E39 forum that the airbag light and code for this problem can be switched off in INPA, Foxwell, etc.
I've messaged 5S0NG as I'd like to get the VIN that the seats came out of so I can figure out exactly which diagram to look at on RealOEM. Hopefully he's up on the board still.
Anyone have any experience with this issue?