seat occupancy code
 

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.

https://i.postimg.cc/fbPwnkJy/seats-new.jpg

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:
https://i.postimg.cc/3wNKc2rz/old-seat-sensor1.jpg

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:
https://i.postimg.cc/JzPrxp8b/new-se...sor-issue1.jpg

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?

I think it's a little more tricky than resistor but most cars you can buy an ass detector simulator. That would be my go-to on having that problem.

You would have to be aware the airbag would likely deploy full force so you would want to never have small passenger in the front seat.

You would also have to either code out the seat belt warning or always buckle the seatbelt.

My wife's old e53 butt sensor would error when the cabin was below freezing and i was pretty sure I'd have to do the seat mat simulator route but we traded the car in first.

Thanks Andrew. I"ve got to get smart on simple coding, now that I've got the full suite of BMW Tools up and running again on my laptop.

These are the related parameters with NCS on airbag module (MRS).

Passenger seat belt buckle:

GURTSCHLOSS_BEIFAHRER_1

GURTSCHLOSS_BEIFAHRER_2

Passenger seat occupancy sensor:

ERKENNUNG_SITZBELEGUNG_1 passenger seat occupation

ERKENNUNG_SITZBELEGUNG_2

SBE1_STATUS_VERZ_1

SBE1_STATUS_VERZ_2

SBE2_1 (this should already be not active)

SBE2_2 (this should already be not active)

The coding would be for seatbelt alarm passenger side.

I often pack my travel bag on my passenger seat so i disabled the seat belt alert for my passenger seat (and set driver alert to 500m). If you use the seat mat simulator box it will tell the car somebody is always in the seat which has a couple issues: 1) seat belt alert when empty 2) airbag will deploy with no person and at full strength.

I think I need to do a deep dive into where the mat is located in the bottom of the seat. Maybe it’s replaceable without tearing the leather off. Perhaps the foam and leather can be removed as one, and the mat then is accessible?

I also still can’t figure out why that little box is missing from the bottom of the new seat. Couldn’t hurt to see if it will plug into the wiring under the seat. The mat side plug though is completely different than the one on the small box.

seat occupancy code
 

People have explored mat replacement and i think I've seen ten threads with only one success story which did involve reupholster.

I replaced my whole seat bottom for $50 but i think you said you replaced the whole seat with incompatible model.

You can look into if the pad just has a different connector and you can swap from old seat. Or: did somebody cut the lead from the seat mat?

Did you say the seats are replaced seats or reupholster? Too manyb threads on seats to keep track.

Look though the parts on realoem you might discover if the mat box is incorporated into the new seat or just was removed. Also: is there a chance parts were swapped? Do you have driver seat bottom on passenger side? Look under your driver seat for the butt sensor box.

The sensor mat is between leather and seat cushion. If reupholstering it would be advisable to renew the mat anyways.

Unfortunately they’ve just been reupholstered and I’m getting the code after swapping them in. I suspect my module is looking for the separate sensor that mounts under the seat and connects between the mat and the car. My car is a 2002 and the seats came from a 2006 (I believe). They don’t have this separate small box. Just ran an inpa sweep and came up with (thanks google translate):
112 seat occupancy determination
Error currently present
Line against plus
Error not sporadic

So yep, seems like the sensor pad is shorting.

Inpa also shows the “see built in” as “yes”. Which tells me the module is smart enough to see that the small box isn’t present on the model seal I swapped in, and it’s just reading a short in the mat.

https://www.bimmerfest.com/threads/p...sensor.614533/

Some good reading.

I understood they are just reupholstered. Just for future reference to someone doing the same I mentioned that the seat mat would be wise to renew at that point.

Every E53 has that small module for seat mat at rear bottom of the seat base. Even my 9/2006 manufactured does. So I don't know why it was missing on your seat.

I agree completely. Wish I would have researched that aspect of my seat project a bit more, but waddya going to do. Not the first time I’ve had to find a work around. Also, RealOEM lists the some of the sensor pads as discontinued.

I did sort out that the seats are from an E70. I thought they were from a 2006 facelifted E53 but the lack of the small module under the seat and the fact that the system has 3 wires (versus 2) that dont match the colors in my Bentley wiring diagrams, threw me off. I recalled however, that I have a BMW wiring diagram app on my phone and after some searching, voila…e70 matches.

So that said, what to do? Guy in Lithuania sells e70 occupancy emulators, which are cheap and I’ll probably order one as a backup. No small kids or car seats will be in the front seat the x5 unless I’ve picked up a random family and we are all fleeing zombie hordes.

Not my first choice though as I’d rather re-program the module to simply ignore the occupancy pad. This is definitely possible with NCS so I watched a few videos yesterday and plugged in to the beast with a sense of optimism that I was finally going to start learning to code my BMW. While INPA worked like a champ, I didn’t get past the module loading step on NCS Dummy, which tells me that my VIN is incorrect, or something like that. I put a call into my Indy to see if he had any experience with this stuff and would take a crack at it.

My new foxwell 710 does have some occupancy sensor programming options, but they quickly got complicated as I worked through the menus, so I’m going to do some additional research before trying this.

If we wanted easy we’d buy Toyotas.

If you have e70 seat and e53 you need e53 seat emulator.

At least now it makes sense and correct no way you can get a new oem butt sensor for 18-25 year old car

I agree, except that I’m not sure how that would work… the e70 plugs are 3 pin/wire and the e53 plugs are 2 wire, that run into either side of the little sensor box under the seat. The e70 seats don’t have the little box.

It looks to me that the e70 seat wiring has a neutral added as the third wire that the e53 seat wiring doesn’t have.

Absolutely unrelated Andrew, but do you know if TIS has m62 rebuild data and information, like crank/cam bearing and other tolerances especially?

What do you mean?

https://www.hubauer-shop.de/en/senso...776921952.html

https://www.leebmann24.com/fi/de/pro...nnung-10395050

I stand corrected. I should have been more clear to say id be shocked (true) if it's available.

I think you are thinking of some adapter to use the e70 seat sensor in e53. That might be possible if the right conditions prevail but the normal fix is a fake seat sensor based on thr car.

Start a thread about rebuild info i can look into it.

Seats looks great!

Is there any chance the seat bases got mixed up and the driver's seat now has the occupancy sensor?

TIS does have this information. The repair procedure references a table which tells you what size bearings to use based on plastigauge measurements. It even lists a permissible deviation in weight from one rod to another.

So freaking comfortable, thanks again for the cloth, it was the right way to go. I love the “heritage” look and will definitely repeat it on whatever I end up building to out my 4.4 into.

I did t think that the seats could be reversed. I’ll definitely though. That would take the seat belt tensioners being reverseable (right?) and my upholstery guy pulling them off and then putting them back on the wrong way. Definitely possible to do, assuming that it’s physically possible.

Will check today.

Willdo...I posted some pics from the initial teardown on the Overland thread, but should probably start an M62 rebuild thread so as not to hijack the overland posts.

So far the motor looks great, especially the bores. A little polishing in them is all I see, but no scoring of any sort that I can feel with my finger/nail. I'm thinking it is most likely then that the low compression I was seeing in two cylinders is from rings or valves. I'll put new rings in it, and lap the valves as part of the process.

I've decided to put 4.6 cams into my heads and build what will essentially be a 4.4 with the 4.6 top end. I'm thinking that 80 or 90% of the 4.6's added HP comes from the heads anyway and putting the rebuild motor into something like an E36 will make for a nice project and a monster when it is done. Maybe 320-330ish HP?

The only difference between the 4.4 and 4.6 heads are the cams and the springs. I've found and bought a set of 4.6 cams, thanks to a forum member, and am looking for a set of 4.6, or aftermarket springs without having to buy the heads too (since mine are in good shape).

New 4.6 springs are available from BMW, but aren't cheap when multiplied by 32. I have one spring on order, along with the retainers, seal and locks so that I can weigh and measure it all, and then try to find a similar and cheaper alternative that will work.

I'm expecting to need new bearings on the crank, at a minimum.

Follow-up and conclusion, hopefully
 

I've had the little resistor from somewhere in eastern Europe sitting in my parts pile for many weeks. Its supposed to emulate a butt in the pax seat, I'm guessing, which will allow the airbag to fire regardless of what size, or if any butt is in the seat.

I was in my storage space yesterday and grabbled the pigtail from the OE seats that I replaced with the facelifted comfort seats. Even though these facelifted seats are much nicer and have a lot more functionality than my OE seats, everything worked when I plugged them into my X5. So I reasoned that the car simply wasn't seeing what it needed to see from the occupancy sensor. Maybe it was code, wiring, a bad pad, or it needed the little box under the seat (that the facelifted occupancy system doesn't have), but whatever the reason I was getting the code and airbag guy in the cluster, my best bet was to put the OE seat wiring back under the new seat, along with the little box with the emulator plugged into it.

The occupancy sensor box has the emulator plugged into one side, and the cable to the bit yellow plug fits right into its designated spot once you pull the protective cover off the back of the plug, and pull the harness that came with the seats, out. I think they are identical harnesses in operation, although since the wire colors were different I figured I'd use the one that was on the seats I took out.
https://i.postimg.cc/7Z0s79J4/PXL-20...-182744667.jpg

I removed the plug assembly from the bracket, unplugged it, and then took the protective cover off the back, which covers all the individual plugs and wires coming from the seat systems. After that it was easy to swap the OE wire with the one that came with the "new" seat. I plugged in the little box, put it all back together, cleared the codes with my foxwell and so far, so good. No little airbag guy, and no SRS codes. Time will tell though. As I recall, it took a while for the light and code to pop after resetting it when I was troubleshooting. I cleaned it all up and snapped it into the plastic holder that is present the "new" seats, even though they don't have this little box.

Mixing ass detector will set abs code immediately. I think you're good to go.


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Hope so. Although it was easier than I thought to ignore that little red airbag dude in the cluster. Way easier than ignoring an SES light.

Update:
More work to do. Went over to pick my wife up at work and was happy not o see airbag guy on my cluster. She gets in the car and buckles up….airbag guy immediately comes back.

I’ll see what the codes are tomorrow, but it seems too coincidental that the tensioner would fail while I’m working on the occupancy issues. I probably need to dig into some wiring diagrams and see where these things intersect. Hopefully there will be some meaningful codes.

How cold where you are? Wife's e53 would air bag man from cold. It was in the module but the error was ass sensor related. When the car warmed up in the cabin power cycle cleared airbag man.


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Interesting…it finally cooled off here, but that just meant it was in the high 60s to low 70s yesterday. It was strange that as soon as her butt hit the seat, or the seatbelt clicked in (wasn’t looking at the cluster when she got in), the MRS guy appeared again. The pad isn’t connected to anything anymore, or so I think. Maybe there is a second connection for the facelifted occupancy mats that I missed.

I read the codes this morning too and was surprised to see the left front side airbag code had set. I’d been fighting this for a year…swapped the plug from the back door (plugs are no longer available), cleaned the connections, etc. but finally bought a new airbag. Fixed…or so I thought.

Once again, super strange that it popped as she got in the car. Maybe her closing the door jiggled something and caused a short.