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      01-09-2015, 04:53 PM   #1
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Replaced battery now airbag light code 93b2?! HELP :(

Replaced battery now airbag light code 93b2?!

i have a 2008 335i coupe e92 with 34km on it. Replaced the original battery a few days ago and programmed the new battery to the car, ever since then the airbag light and seat belt light remain on ..., scanned it with bmwhat app code is 93b2 safety battery terminal.

checked all connections everything looks fine. Done a bunch of research and people say its either the BST cable or the distribution board on the battery. I replaced both yesterday and tried to clear the code. NO CHANGE both airbag light and seatbelt light are solid.

iv checked everything over many times,have read any threads i can find online with people with similar problems.

ANY SUGGESTIONS ARE APPRECIATED. Thanks a lot
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      01-09-2015, 08:14 PM   #2
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If you are getting this:

93B2 ZK10 / Sicherheitsbatterieklemme
...
widerstand zu gross (ZK)

In English:

93B2 ZK10 / safety battery terminal
....
resistant to large (ZK)


I had this last winter after replacing battery, and this winter when it got cold.

This is because of that tiny connector that goes into the BST (Battery safety terminal), which is the end section of the thick red positive cable that goes into the positive battery post.

In addition to the thick red positive table, there is another thin two wire cable that gets connected to the BST. The code means whether this connector is not placed back, or it is connected but not seated well and making good connection. In my case it was the later.

First make sure you have this tiny wire is connected to the place on BST. If it is connected remove it carefully, spray its pins and the pins on the connector on the BST side for it with a good electrical contact cleaner. Then pry up the two prongy things on the connector that is supposed to keep it tightly seated in its place. And place it back on the BST. Then clear the code and see how it goes.

Last year I had accidentally knocked this tiny thing off from the BST during battery replacement and once removed they get loose. I had cleaned the connector and made it seat well that time which was fine till this winter. This winter from cold looks like it again got lost its connection, I removed it again, cleaned both sides again with contact cleaner, pried up those things on the tiny connector and seated it back, cleared code and it hasn't came back again.

The code is very descriptive in your and my case.

One other possibility wherever the other side of this cable is ending up (probably in the air bag central control system, don't know where it is, but could find it) has a loose connection, but that is low possibility, because you had the problem occur after battery replacement.

I don't know if BMW sells that flimsy tiny connector alone.

I read there is an option of tricking this by connecting a 2 ohm fuse at that wire and not connecting it to the BST, but I don't recommend it unless you can't fix it otherwise. This wire, as you probably already know, in case of an accident is used to fires up a pyrotechnic small device inside the BST which forces the positive battery cable out of the battery post connection (from outside would still look like connected though), and is meant to protect any fire.
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      01-09-2015, 08:56 PM   #3
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Quote:
Originally Posted by PhaseP View Post
If you are getting this:

93B2 ZK10 / Sicherheitsbatterieklemme
...
widerstand zu gross (ZK)

In English:

93B2 ZK10 / safety battery terminal
....
resistant to large (ZK)


I had this last winter after replacing battery, and this winter when it got cold.

This is because of that tiny connector that goes into the BST (Battery safety terminal), which is the end section of the thick red positive cable that goes into the positive battery post.

In addition to the thick red positive table, there is another thin two wire cable that gets connected to the BST. The code means whether this connector is not placed back, or it is connected but not seated well and making good connection. In my case it was the later.

First make sure you have this tiny wire is connected to the place on BST. If it is connected remove it carefully, spray its pins and the pins on the connector on the BST side for it with a good electrical contact cleaner. Then pry up the two prongy things on the connector that is supposed to keep it tightly seated in its place. And place it back on the BST. Then clear the code and see how it goes.

Last year I had accidentally knocked this tiny thing off from the BST during battery replacement and once removed they get loose. I had cleaned the connector and made it seat well that time which was fine till this winter. This winter from cold looks like it again got lost its connection, I removed it again, cleaned both sides again with contact cleaner, pried up those things on the tiny connector and seated it back, cleared code and it hasn't came back again.

The code is very descriptive in your and my case.

One other possibility wherever the other side of this cable is ending up (probably in the air bag central control system, don't know where it is, but could find it) has a loose connection, but that is low possibility, because you had the problem occur after battery replacement.

I don't know if BMW sells that flimsy tiny connector alone.

I read there is an option of tricking this by connecting a 2 ohm fuse at that wire and not connecting it to the BST, but I don't recommend it unless you can't fix it otherwise. This wire, as you probably already know, in case of an accident is used to fires up a pyrotechnic small device inside the BST which forces the positive battery cable out of the battery post connection (from outside would still look like connected though), and is meant to protect any fire.

Thank you very much for your in depth reply.

Yes this connector is VERY flimsy and I'm pulling my hair out trying to figure out the problem. When you say pry up on the pins your talking about the pins on the actual female port on the positive terminal not the 2 wire connection coming from the car?
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      01-09-2015, 10:47 PM   #4
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UPDATE:
Problem fixed, pride up on the gold pins to ensure contact is made, put everything together and reset the code with bmwhat app and wifi obd2.
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      07-29-2018, 10:29 PM   #5
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Quote:
Originally Posted by 335inYEG View Post
UPDATE:
Problem fixed, pride up on the gold pins to ensure contact is made, put everything together and reset the code with bmwhat app and wifi obd2.
Could you post a picture of the gold pins that you are referring to?

I am having the same issue.
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      12-12-2018, 09:49 PM   #6
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Same issue here, any pictures would be appreciated!

Thx!
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      12-13-2018, 03:04 AM   #7
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If it is like the Takata style connectors, they have a safety bridge across the pins which get lifted away when the squib is connected.
It is to prevent accidental detonation by static electricity but if your squib is damaged or someone has tampered with it before, the tab which lifts the bridge may be missing.

See the two tabs above the pins in this pic: http://bmwcentrum.pl/img/products/65/7/1_max.jpg
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      12-13-2018, 05:40 PM   #8
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This below picture has been my final solution. Because after I had fixed it by cleaning the contacts with contact cleaner spray and spreading the pins a bit to make better contact, a year later with winter same code came back.
Then I wrapped it tight pushing into the female side on the BST with electrical tape. No codes ever since.
It is the black electrical tape on the picture. Ignore the small piece of blue painters tape left over from while doing battery replacement (2nd one) Battery is out in the picture as you can tell.
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      04-06-2019, 09:57 PM   #9
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Updating this thread with some helpful info if anyone has this issue in the future...

I was able to code the BST error out with BimmerGeeks Protool the other day.
1. Connect to the car with Protool
2. Select "Airbag"
3. Select "Coding"
4. Set "Battery Safety Terminal" to "Not Active
5. Select "Finalize Coding" and cycle ignition to the car.

Hope this help someone!
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      04-27-2019, 05:03 PM   #10
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Quote:
Originally Posted by Skers 05 View Post
Updating this thread with some helpful info if anyone has this issue in the future...

I was able to code the BST error out with BimmerGeeks Protool the other day.
1. Connect to the car with Protool
2. Select "Airbag"
3. Select "Coding"
4. Set "Battery Safety Terminal" to "Not Active
5. Select "Finalize Coding" and cycle ignition to the car.

Hope this help someone!
By doing this does this deactivate the airbag as well?


Edit: I followed those instructions and all it did was make the light and error stay and couldn't clear it out
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      06-21-2019, 09:58 PM   #11
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Bumping this thread because it just helped me. Last week I replaced the seals in the transmission between the mechatronic and the trans housing. I had a heck of a time getting the car back together and running after, and in my misadventures I had to disconnect and reconnect the battery a few times. The battery bled down while diagnosing, and I charged it at the nut that retains the various sensors on the top of the battery. This is not a good idea, but in the heat of the moment I forgot. 2 Days after my repair job I got the airbag and seatbelt light, but no other issues. I pulled the following error codes:
93d2 93fb 93b2

There isnt much information out there for 93fb, but seemingly it's a wheelspeed sensor. This was unlikely my issue. 93d2 is the passenger airbag, and I thought this could be the issue. However, I know my car hasn't had any issues with the seat mat thus far so I was skeptical for this as the issue. 93b2 is the bst, and i figured this was my most probable cause given that I was messing with the battery a bunch and charged it at a spot it shouldnt have been charged at.

The BST itself seems to be nearly impossible to disassemble without destroying the plastic casing. The 2 wires mentioned here are connected to the top of the battery power distribution box, so that's where I unplugged the connector and re-jigged the pins to try and make better contact. This was all with the battery disconnected. After hooking everything back up I still saw the airbag fault on the dash, so I cleared codes on the airbag module with INPA. The airbag light turned off. I started the car and just took it for a quick spin, it seems as if the fault is gone. If the fault comes back I might try doing this once again and coating the pins with some dielectric grease. Beyond that, my BST may need replacing.
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      07-11-2019, 04:29 PM   #12
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Hello All, I want to thank you, PhaseP, as the electric tape solution worked for me on my E90. I had my battery replaced and they wanted close to $900 to replace both positive and negative battery cables. From your pictures and description, I was able to locate the BST although I could not disconnect it. I pushed it in, wrapped in tightly with electrical tape and cleared the codes. Now no airbag and seat belt error lights. Saved a lot of cash too. Thank you!
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      07-22-2019, 04:57 AM   #13
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Hi all, my positive terminal seems slightly different than the pics posted here. Here's a pic of what it looks like, is circle 1 the connector causing the issue or the connection at circle 2?
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      07-22-2019, 08:59 AM   #14
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My issue was with the little connector labelled #2 above. The actual BST is the one labelled 1. Other than just pushing this connector back in to place I don't think this can really be serviced. Rejigging the pins happens on connector 2.
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      07-22-2019, 10:09 AM   #15
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Quote:
Originally Posted by Ekulz View Post
Hi all, my positive terminal seems slightly different than the pics posted here. Here's a pic of what it looks like, is circle 1 the connector causing the issue or the connection at circle 2?
You have the early style black BST which is no longer made. I had issue with the connection at circle 2. Once cleaned, my light no longer comes on.

If your BST is bad and you replace with the new style, you will need a new wiring pigtail. New style BST do not have a connector at circle 2 and the wires can't be removed from your current BST. The 2 wires after circle 2 connection are cut, re-soldered and shrink wrapped to new wiring. I got some wiring from a local wreck in case my light comes back.
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      07-22-2019, 07:12 PM   #16
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Thanks all for the responses. I gave connection #2 a quick clean and cleared the codes. If it comes back I'll play with the pins and possibly tighten the connection with some electrical tape

This actually happened after I had my rear bumper replaced by the panel beaters from someone rear ending me. I think they disconnected the battery as part of removing the tail lights, and maybe they weren't so careful in doing this. If I can't get the code to stay away I'll probably just contact my insurance again and see what can be done
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      11-26-2019, 07:44 PM   #17
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Quote:
Originally Posted by Ekulz View Post
Hi all, my positive terminal seems slightly different than the pics posted here. Here's a pic of what it looks like, is circle 1 the connector causing the issue or the connection at circle 2?
I have the same old-style/early version of the BST on 2006 330i, and I recently fixed this same issue by replacing the airbag signal wiring without changing the BST. It began throwing the code intermittently, then I found by routing the wire differently I could get the code to stay away for weeks. Eventually though, the code would always come back after a day, and so I needed to find a proper solution.

Contrary to popular belief, the short 6" detonation signal wiring from the airbag wiring outlet to the BST is removable from the BST, even on the old version where the black plastic case tries to prevent you from doing so. You can get a new wire that fits the BST from BMW parts dealers under part # 61129130178 for about $45. (if you have special crimping tools, you also can buy the airbag wire connectors and make a new wire yourself, but I don't recommend that). However, the new wire, as sold, is crazy long (like 20 feet!) and does not have the Takata black/yellow plug on the other end. It does, however, have the proper metal connectors crimped onto the other end to fit into your old wire's plug. Changing the wire is thus a pain, but it is possible, and I did it!


Here's my instructions:

You're going to have remove the battery and unbolt the BST's battery cable from the bottom back wall of the battery compartment so you can work on it at a table. First, you'll probably want to get that darn wiring disconnected from the bulky BST. The plug does comes out, just not the way you might expect it to, as it is 90-degrees airbag connector and you have to pull it up to get it out. The black plastic housing of the old style BST blocks you from taking it out, however, as it doesn't unsnap open as far as I can tell! (and if you break it open, the BST might not work correctly if it gets triggered, as you'll notice there are plastic clips built in to the plastic housing to stop the BST from falling back in and reconnecting the power after it is fired out). However, on the end where the signal wiring goes in, it is flexible plastic that doesn't crack and can be twisted out with nose pliers to make enough room to slide out the old connector and insert the new connector. There are also locking tabs on the sides of the plug itself, of course, and those broke off as I pried the plug out as I didn't have an extra hand to tweeze them while I pried the connector out (not re-using that, so I don't care in this case). Once you have the old plug out, you can then slide the new wire's plug in, push it in all the way until the locking tabs click. Then you can bend the plastic casing back into place again, I was amazed that I could not even tell it had been previously bent open!

The job is now half done. For the other end, you're going to have to open and take apart the black/yellow Takata connector plug so you can re-install it on the new wiring. It comes apart fairly easily, but you need to remove several small parts, including the safety bridge plate, before you can finally pull out the two wires. Note: Both wires are black, which I think means polarity doesn't matter, but just to be sure, I removed pin #1 first and wrapped black tape around both ends of it before removing pin #2, so I could keep polarity the same when inserting the new wires. The pins on the new wire were tight to slide in to the old Takata plug housing, and they must go in all the way up or you won't be able to close the connector properly.

Once done, I think you're supposed to shorten the wire to desired length by cutting it in the middle and solder the ends back together, but I'm not good at that sort of thing, so I just wrapped the wire in a bundle and dropped it alongside the battery. After re-installing the BST, the battery, and resetting the airbag module, I have not seen the BST error return! Even with the 20 foot run of wiring between them.

BTW - examining the old wires carefully, I did not see any visible damage or corrosion issues with the wire or crimped connectors. The wire had become stiff in the curvature of the installation, which is what I suspected may be the issue. Checking resistance, each individual wire seems to read over 1 ohm of resistance! (just for a 6" run) The exact value also changes by about .5 ohm if you wiggle it or straighten it. That must be what the computer has been seeing to throw the error code. I'm assuming this is caused by some hairline fractures or internal corrosion under the wire's insulation. However, it also suggests you could bypass the BST by simply shorting the wires at the BST end, since the internal resistance of the two wires is already over 2 ohms! (albeit, not constant value) I haven't tried doing that though.

That's my story, quite amazing in my humble opinion, hope this helps someone and good luck!
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      11-26-2019, 07:51 PM   #18
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Quote:
Originally Posted by leif20 View Post
If the fault comes back I might try doing this once again and coating the pins with some dielectric grease.
BTW - I was recently surprised to learn while doing a tune-up that dielectric grease is an insulator and does not conduct electricity! Rather, it is used to harden and seal internal connections from outside moisture.

Therefore, putting it on low voltage pins is a very bad idea! There is a special type of grease substance that does conduct electricity and might help here, but definitely not standard dielectric grease.
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      12-12-2019, 06:02 PM   #19
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Bump. Hey I'm having the zk10 error on my e92 335i. The 2 pin bst cable is plugged in and secure but inpa refuses to clear the codes. The car was in a front end collision I dont think it was enought to trigger the airbags and there was 2 bst cables in the trunk. I measure the resistance on the connector for both and there was some resistance cant remeber how much but they were about the same. Anyways both cables give the car power but the error is still there any suggestions?
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      02-05-2020, 08:44 PM   #20
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Quote:
Originally Posted by cparke View Post
I have the same old-style/early version of the BST on 2006 330i, and I recently fixed this same issue by replacing the airbag signal wiring without changing the BST. It began throwing the code intermittently, then I found by routing the wire differently I could get the code to stay away for weeks. Eventually though, the code would always come back after a day, and so I needed to find a proper solution.

Contrary to popular belief, the short 6" detonation signal wiring from the airbag wiring outlet to the BST is removable from the BST, even on the old version where the black plastic case tries to prevent you from doing so. You can get a new wire that fits the BST from BMW parts dealers under part # 61129130178 for about $45. (if you have special crimping tools, you also can buy the airbag wire connectors and make a new wire yourself, but I don't recommend that). However, the new wire, as sold, is crazy long (like 20 feet!) and does not have the Takata black/yellow plug on the other end. It does, however, have the proper metal connectors crimped onto the other end to fit into your old wire's plug. Changing the wire is thus a pain, but it is possible, and I did it!


Here's my instructions:

You're going to have remove the battery and unbolt the BST's battery cable from the bottom back wall of the battery compartment so you can work on it at a table. First, you'll probably want to get that darn wiring disconnected from the bulky BST. The plug does comes out, just not the way you might expect it to, as it is 90-degrees airbag connector and you have to pull it up to get it out. The black plastic housing of the old style BST blocks you from taking it out, however, as it doesn't unsnap open as far as I can tell! (and if you break it open, the BST might not work correctly if it gets triggered, as you'll notice there are plastic clips built in to the plastic housing to stop the BST from falling back in and reconnecting the power after it is fired out). However, on the end where the signal wiring goes in, it is flexible plastic that doesn't crack and can be twisted out with nose pliers to make enough room to slide out the old connector and insert the new connector. There are also locking tabs on the sides of the plug itself, of course, and those broke off as I pried the plug out as I didn't have an extra hand to tweeze them while I pried the connector out (not re-using that, so I don't care in this case). Once you have the old plug out, you can then slide the new wire's plug in, push it in all the way until the locking tabs click. Then you can bend the plastic casing back into place again, I was amazed that I could not even tell it had been previously bent open!

The job is now half done. For the other end, you're going to have to open and take apart the black/yellow Takata connector plug so you can re-install it on the new wiring. It comes apart fairly easily, but you need to remove several small parts, including the safety bridge plate, before you can finally pull out the two wires. Note: Both wires are black, which I think means polarity doesn't matter, but just to be sure, I removed pin #1 first and wrapped black tape around both ends of it before removing pin #2, so I could keep polarity the same when inserting the new wires. The pins on the new wire were tight to slide in to the old Takata plug housing, and they must go in all the way up or you won't be able to close the connector properly.

Once done, I think you're supposed to shorten the wire to desired length by cutting it in the middle and solder the ends back together, but I'm not good at that sort of thing, so I just wrapped the wire in a bundle and dropped it alongside the battery. After re-installing the BST, the battery, and resetting the airbag module, I have not seen the BST error return! Even with the 20 foot run of wiring between them.

BTW - examining the old wires carefully, I did not see any visible damage or corrosion issues with the wire or crimped connectors. The wire had become stiff in the curvature of the installation, which is what I suspected may be the issue. Checking resistance, each individual wire seems to read over 1 ohm of resistance! (just for a 6" run) The exact value also changes by about .5 ohm if you wiggle it or straighten it. That must be what the computer has been seeing to throw the error code. I'm assuming this is caused by some hairline fractures or internal corrosion under the wire's insulation. However, it also suggests you could bypass the BST by simply shorting the wires at the BST end, since the internal resistance of the two wires is already over 2 ohms! (albeit, not constant value) I haven't tried doing that though.

That's my story, quite amazing in my humble opinion, hope this helps someone and good luck!
Amazing thank you for the detailed info. Mine is doing the same thing, it used to stay away for months, then weeks, and now it keeps coming back every day after I clear the codes.

I'm trying to sell the car as I'm going overseas, so this is not ideal. I'll have to give this a try. Have you had the error come back after replacing this wire?
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      02-19-2020, 09:34 PM   #21
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Just to help anyone with this problem I manage to solve it by changing the connector by soldering the wire to XT30 connector. Before you determine if this method work, you need to measure the resistance first. If you look at the picture above, the connector I remove is the the yellow connector that's in a black casing. Take the yellow connector out and remove the pin from the connector. You can do this using a small flat screwdriver and press down the pin and pull out. Measure both removed pin and if the resistant is around 2 - 6 ohm then you have no problem with the BST fuse. There are 2 problem that exist here. First is the pin connection is loose where bending it might tighten the connection. Another problem is there is a metal in the black plastic jacket that will short both pin if it's not inserted properly to another connector. If you read 0 ohm from the INPA, most likely this is the problem. To resolved this loose connection or shorted pin issue, just splice the wire and connect using XT30 connector. Then just clear the error code with INPA or any third party tools that can clear the error code.
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Last edited by pierreye; 02-19-2020 at 09:39 PM..
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      07-18-2020, 03:20 PM   #22
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Quote:
Originally Posted by cparke View Post
I have the same old-style/early version of the BST on 2006 330i, and I recently fixed this same issue by replacing the airbag signal wiring without changing the BST.
UPDATE: After about 3 months, the BST error and airbag indicator came back for me even with the new wiring. However, I still do not believe the BST itself is the culrpit. Rather this seems to be an electrical contact issue at the black/yellow Tyco connection with the vehicle's wiring hardness, like the previous poster described.

Using grabbing test clips and alligator test leads, I temporarily bypassed the connectors to verify that this is indeed the point of failure. Soldering the line to the main wire harness like previous poster did is definitely an option, or changing out the connectors for a new set of airbag wiring connectors is also possible. However, I personally would prefer to stay with the original connectors if possible.

The main issue that I think is causing this problem for me is that my battery is not tied down properly because past accident damage to the rear right of the vehicle caused deformities in the battery compartment, and the tie down hardware will not fit correctly anymore. So, my battery can jump up on bumps or slide forwards and backwards slightly on hills, and indeed it was in such situations that my airbag errors originally got thrown. I've tried to reduce the battery's sliding by confining it to a smaller area in the compartment with inserts, but still the fact is that the battery will move slightly from time to time. I'm also not using a genuine BMW battery right now, so it may be a perfect fit like it is supposed to be. As a result, with the battery compartment's cover in place in the trunk, I think the BST signal wire connector that sits on the top of battery distribution tray is getting squeezed and stressed at these times, and that is causing the slight loosening of the connector with the pins that creates this error.

My next steps, therefore, are to try to tighten the female connectors that the pins go into to repair the minor damage that must have occurred. Then, I plan to discontinue placing the connector on top of the power distribution and try instead to keep it on the side of the battery (in my battery compartment, because of the damage, the battery can't slide left and right to the side edges, so there is space there that I can use). Hoping once that is done it will be the end of this BST error for me for a long, long time!


P.S. I also would comment that there is indeed a shorting clip inside the Tyco connectors that activates whenever the connector is unplugged, as the previous poster described. This is an airbag system wiring standard to prevent accidental detonation when connecting or disconnecting. These metal clips make it hard to check resistance through the plugs and connectors when the system is disconnected; you should get 0 resistance between the terminals because of the clip. There is another clip inside the BST itself where the signal wire plugs in, for the same reason. These metal clips themselves can cause the BST airbag error to get thrown if the connectors are not plugged in all the way in order to fully disengage the clip. And that can happen when someone who doesn't know what they're doing (which was me when I first got the car) tries to unplug the signal wiring at the BST end and can't get it out, gives up, and finds the other, proper way. The clip can be removed, and I tried that just to see, but it did not help my problem.

Last edited by cparke; 07-18-2020 at 03:25 PM..
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