I spent some time today to track down the single most annoying aspect of this car and remove it. The warning chime that goes off every time you start the car, open a door, leave the key in the ignition, move without having a seatbelt on, ... the list goes on. Heck, it even chimes to tell you its cold outside. The sound is ear piercing and had to be removed.

I tracked down the source of the sound to be from a small metal tweeter built into the rear of the gauge cluster assembly.
In order to get to it, you need to pull out the assembly, which is held in by 1 T-20 screw at the very top of the gauges, between the two protrusions of the tach and speedo. There is a slide clip that holds its harness into place. After you remove it, you have to open the assembly by removing 4 x T-8 screws, and then popping 5 plastic clips with a flat screwdriver.

http://img218.imageshack.us/img218/4632/bmw226te3.jpg

Unfortunatly the tweeter is not a separate speaker or attached via a harness, instead it is soldered directly into the cluster board PCB. However, all it has is a + and - lead, so the control for it is held elsewhere on the board. Since it is apparent at this point that it is only speaker, it is OK to disable it by breaking one of the leads. I twisted it carefully by hand and snapped the + lead. Put a piece of electrical tape between the now broken lead and the speaker, and then re-assemble everything. No more chiming!

http://img162.imageshack.us/img162/8915/bmw227tg3.jpg

You don't even need to pull the battery to do this. You won't get a CEL, thrown any codes, or anything. If you ever want to undo this mod, just solder a small lead wire between the lead you broke and the other side of it on the tweeter. Enjoy the silence and hearing nothing but the engine on startup!

Awesome mod. Funny how it was also the first thing I did to my E30, the speaker comes in its own box under the dash so you can just unplug it.

I don't have any annoying chimes on mine. 1 day I forgot to put the seatbelt on right away and heard it and am glad I did. The radio works without keys so I never hear that chime if I'm washing it or something, I don't need keys in the ignition. The only other chime I hear is if I leave the parking lights on on purpose and pull they keys out. Nothing I ever think twice about. I get no chimes on engine start up at all. Maybe on the 06's + it is not that much of an annoyance?

Speaking of the chime, I took my newly acquired 03 out this weekend, and after a run through the mountains pulled it into the driveway and let it stand for about 5 minutes with the top down (just painting the picture), got back in to leave and the buzzer went off, nothing would stop it - seatbelts, lock unlock, start up turn off, close roof, it just carried on for 5 minutes - no warning lights or anything else amiss. Then it stopped???

E-Brake perhaps? Door open? Top not fully down/up? Few things I can think of, my 07 definitely has a bunch of chimes when I start up.

Speaking of the chime, I took my newly acquired 03 out this weekend, and after a run through the mountains pulled it into the driveway and let it stand for about 5 minutes with the top down (just painting the picture), got back in to leave and the buzzer went off, nothing would stop it - seatbelts, lock unlock, start up turn off, close roof, it just carried on for 5 minutes - no warning lights or anything else amiss. Then it stopped???

this is a known issue. nobody knows the cause. at least i'm fairly sure nobody knows.

anyways, good mod OP.