93b2 ошибка бмв e90

Drives: 2006 BMW 330i N52

Join Date: Oct 2017

Location: New York

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!