Results 1 to 11 of 11

Thread: Seat cushion swap with Airbag mat sensor? Now what?

  1. #1
    Join Date
    Aug 2003
    Location
    Woodinville, WA
    Posts
    724
    My Cars
    '87 L6, '97 840, '02 M5

    Seat cushion swap with Airbag mat sensor? Now what?

    Working on a '98 BMW 328i with electric sports seats.

    Pulled both seats tonight to do the seat bun swap. Was planning to use the passenger side seat bun on the drivers side (which has a bad bolster but good leather) and swap the drivers side over.

    When I pulled the bottom seat cushion on the passenger side, I noticed an electrical connection coming off the back of the foam. I wrongly assumed that someone had put a heated seat in at some point, and happily swapped the bottoms. Feels great to have fresh foam!

    Well I'm on REALOEM and I realize that's actually a mat sensor for the drivers side airbag! Gah. Is that seat sensor required to be plugged in? Anyone dealt with this before and what did you do?

    Thanks!
    Last edited by Corellian Corve; 12-02-2016 at 01:54 AM.
    1987 L6
    1997 840ci
    2000 740i Sport
    2000 M Roadster
    2001 M5
    2002 540i Sport
    2002 X5 4.6is
    2003 530i Sport
    2003 M3
    2003 Z3 3.0
    2005 X5 3.0 Sport

  2. #2
    Join Date
    Sep 2014
    Location
    Poland
    Posts
    38
    My Cars
    1998 BMW E36 Compact
    Hi

    I don't know if I understand correct
    You have only one sensor mat ??
    There should be two, on both seats
    Check wiring under seat, how it is connected. If you need pictures of sensor mats connection i can send you.

    If sensor mat is not connected, airbag error light shows up (except compact, which does not use sensor mats)
    Maybe someone has connected sensor emulator on one side ?
    Last edited by fold; 12-02-2016 at 04:06 AM.

  3. #3
    Join Date
    Aug 2003
    Location
    Woodinville, WA
    Posts
    724
    My Cars
    '87 L6, '97 840, '02 M5
    Yes, only the passenger side seat has the sensor. It's a thin wire looks like a seat heater element.

    Is there a defeat for this?

  4. #4
    Join Date
    Sep 2014
    Location
    Poland
    Posts
    38
    My Cars
    1998 BMW E36 Compact
    First tell Me, does airbag light works as it should in your car?
    If yes, then someone Has attached sensor emulator and you can leave it like that. If you want to do it right, you should buy working sensor for second seat and connect it.
    Do you have any diag tool? Check airbag unit for errors

    Ps. I've got spare sensor, if you are interested send me pm

  5. #5
    Join Date
    Jul 2010
    Location
    Murrieta, CA
    Posts
    9,530
    My Cars
    '94 325iC, '08 328i, E93
    Quote Originally Posted by Corellian Corve View Post
    Working on a '98 BMW 328i with electric sports seats.

    Pulled both seats tonight to do the seat bun swap. Was planning to use the passenger side seat bun on the drivers side (which has a bad bolster but good leather) and swap the drivers side over.

    When I pulled the bottom seat cushion on the passenger side, I noticed an electrical connection coming off the back of the foam. I wrongly assumed that someone had put a heated seat in at some point, and happily swapped the bottoms. Feels great to have fresh foam!

    Well I'm on REALOEM and I realize that's actually a mat sensor for the drivers side airbag! Gah. Is that seat sensor required to be plugged in? Anyone dealt with this before and what did you do?

    Thanks!

    I'm confused. Again. The driver seat does not need an occupancy sensor because without a driver the car is not going anywhere. If there's a chance that the airbag might be needed, there will be a driver in the seat. This is a guaranteed condition. There may or may not be a passenger, but there will always be a driver.

    When you pulled the passenger side seat bottom and found a connector, this is the seat occupancy sensor for the passenger seat. Are you asking about the same connector existing on the driver seat bottom? It might just be me, but your post is confusing.

  6. #6
    Join Date
    May 2008
    Location
    Trumbull CT
    Posts
    1,615
    My Cars
    1998 M3 Vert, 1992 318i
    JD is right, there is only a sensor on the passenger seat.
    Caprica Junkie

  7. #7
    Join Date
    Sep 2014
    Location
    Poland
    Posts
    38
    My Cars
    1998 BMW E36 Compact
    I have disassembled on my own seats from 2 bmws with side airbags
    Both had sensor mats on driver seat
    Realoem info is also confusing...
    That's all i know

  8. #8
    Join Date
    Aug 2003
    Location
    Woodinville, WA
    Posts
    724
    My Cars
    '87 L6, '97 840, '02 M5
    Ok sorry if this was confusing. I've solved the problem so I'll start again.

    I wanted to swap seat foam bases in my '98 328i. I've read the DIY's that said it was simple so I pulled the seats to swap.

    What the DIY's didn't mention is that some passenger seat bases have SRS seat sensors. So I wasn't sure what to do since I'd already re-installed the drivers seat with passenger foam base and was hoping to not have to reverse the procedure.

    Well my car did have an intermittent SRS warning light come on occasionally. Most likely due to a faulty seat sensor per INPA. I just didn't put 2+2 together.

    I decided to install one of the SRS seat sensor delete plugs from eBay. I'm not going to spend the $$ to replace the mat, I won't have kids sitting in the front seat of this car only adults so should be fine.

    So I guess that's the answer. If you want to swap passenger-to-drivers seat cushions, you either need to swap the seat sensor OR install one of the SRS bypass plugs.
    Last edited by Corellian Corve; 12-03-2016 at 02:02 PM.
    1987 L6
    1997 840ci
    2000 740i Sport
    2000 M Roadster
    2001 M5
    2002 540i Sport
    2002 X5 4.6is
    2003 530i Sport
    2003 M3
    2003 Z3 3.0
    2005 X5 3.0 Sport

  9. #9
    Join Date
    Jun 2010
    Location
    Hillsboro, OR
    Posts
    97
    My Cars
    1999 BMW M3 Coupe

    Cushion swap Driver/Passenger - swap SRS sensor too?

    Quote Originally Posted by Corellian Corve View Post
    Ok sorry if this was confusing. I've solved the problem so I'll start again.

    I wanted to swap seat foam bases in my '98 328i. I've read the DIY's that said it was simple so I pulled the seats to swap.

    What the DIY's didn't mention is that some passenger seat bases have SRS seat sensors. So I wasn't sure what to do since I'd already re-installed the drivers seat with passenger foam base and was hoping to not have to reverse the procedure.

    Well my car did have an intermittent SRS warning light come on occasionally. Most likely due to a faulty seat sensor per INPA. I just didn't put 2+2 together.

    I decided to install one of the SRS seat sensor delete plugs from eBay. I'm not going to spend the $$ to replace the mat, I won't have kids sitting in the front seat of this car only adults so should be fine.

    So I guess that's the answer. If you want to swap passenger-to-drivers seat cushions, you either need to swap the seat sensor OR install one of the SRS bypass plugs.

    I was just about to (and glad I didn't) try swapping seat cushions because the Vader driver's side bolster is not in as good a condition as the passenger seat cushions (seat and back). Old thread, I know, but I have not read about this SRS sensor detail anywhere else. I'd like to know who else has successfully done this cushion swap while retaining the SRS sensor on the passenger side.

    Update: 2 yrs later, still no problem with the SRS light coming on after installing a SRS delete plug off of Ebay as mentioned above. I did the seat cushion swap, as well as the back/bolsters, and refinished the leather with a water based dye. Everything came out sweet, but it was a ton of work. I should mention that I do have a laptop setup to use INPA and other tools to reset the SRS fault code, but it kept tripping. The SRS delete plug was the economical solution, which I understand makes the passenger side airbags deploy in an accident regardless of whether there was a passenger sitting in the seat. Is that a bad thing? I'd like to know.
    Last edited by trading10; 06-08-2020 at 08:42 AM. Reason: Update

  10. #10
    Join Date
    Oct 2003
    Location
    New Zealand
    Posts
    266
    My Cars
    1996 E36 M3 Evo
    Quote Originally Posted by trading10 View Post
    I was just about to (and glad I didn't) try swapping seat cushions because the Vader driver's side bolster is not in as good a condition as the passenger seat cushions (seat and back). Old thread, I know, but I have not read about this SRS sensor detail anywhere else. I'd like to know who else has successfully done this cushion swap while retaining the SRS sensor on the passenger side.
    The occupancy sensor is under the cushion so if you're swapping over the cushions only you don't need to touch the sensor at all.

    In the event that you screw up the sensor somehow you can get a plug in bypass on eBay for about $8.

    If you're going to disconnect the sensor make sure you disconnect the battery first so you don't trigger the airbag/SRS light.
    '96 M3, S50B32, 6MT
    + good stuff

  11. #11
    Join Date
    May 2006
    Location
    The Netherlands
    Posts
    16,710
    My Cars
    DE-spec E36 328i/M3 cab
    Just to be clear, there is no driver's side occupancy sensor mat, regardless of side airbags or not.

    As mentioned, if the car is moving, there is a driver inside.

    The part is also designated "Sensor mat f co-driver's seat identif." / quantity 1.

    If you find one in your driver's seat, someone swapped it in.

    And to add, my car has side airbags and no connector for the little black control box that is under the passenger's seat.
    1998 BMW M3 3.2 Cabrio • Alpinweiί III on Schwarz • German spec • 1 of 12
    SMG • SRA • PDC • AUC • OBC • GSM • HK • UURS • IHKA • FGR • MFL

    IG:
    https://www.instagram.com/iflok/



Similar Threads

  1. Seat cushion swap question
    By Dash01 in forum 1976 - 1989 (E24)
    Replies: 2
    Last Post: 07-16-2014, 10:18 PM
  2. Airbag is out... Now what do I do with it?
    By ptc075 in forum Georgia sponsored by Harrison Motorsports
    Replies: 7
    Last Post: 02-28-2011, 05:39 PM
  3. 1996 328is passenger-driver seat cushion swap
    By berkeleyEE in forum 1991 - 1999 (E36)
    Replies: 4
    Last Post: 07-16-2008, 07:50 PM
  4. Airbag warning light...now what
    By BMWManiac in forum 1992 - 1999 M3 (E36)
    Replies: 2
    Last Post: 12-11-2005, 05:15 PM
  5. Slept with gf's friend, now what?
    By mace in forum Off-Topic
    Replies: 54
    Last Post: 12-01-2002, 11:08 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •