I have BMW 330ci, the central locking does not work. Bmw fixed it in a matter of seconds last time it happened but it is expensive. Can i reset the key fob myself ?

Check fuses first, then check the wiring connections to the buttons. Possible the plugs are corroded and just need to be unplugged, cleaned, and plugged back in.

i cnt set my central locking to open 1 door and second time 3 doors open

the horn on my 2005 330 ci keeps going off by it self.

I'm having the same problem have you fixed yours?

starter motor, ignition switch, starter relay, fuse connections.

Providing central locking works when you insert key in lock,try programming keys
Enter car make sure all doors/windows are shut
Switch ignition on and off,remove key
PRESS AND HOLD UNLOCK BUTTON ON KEY
Press lock button on key 3 times whithin 10 seconds and release unlock
Central locking will lock/unlock rapidly to confirm reset
If your key is the type with bmw logo in the middle battery replacement is not possible,as it charges as you drive

how do i reset the key on central locking on a bmw 3 series 1999??

You must reset your remote control in order for the lock/unlock to work properly.

To reset remote you would:
1)Insert Key in Ignition Turn to Position 1(Don't Start the Engine) for about 5 seconds
2)Turn Key Off and HOLD the LOCK button on Remote while pressing the UNLOCK 3 TIMES
3)Release both lock and unlock buttons you are holding
4)All doors should automatically unlock

And exit the door and lock with the Remote.

I have an 01 330ci and a similar thing happened to me... The dealership indicated that they have only ever replaced a handful of actual fans in these cars (and that they're tucked down deep in the dash...) but my issue was what they referred to as the "final stage unit." It was this bulky multi-pronged metal plug that went in behind the glove box. I believe it only cost me about $80-$90 from the dealership last summer. And I think only an hours labor from the mechanic I used.

Your torque converter is not locking up.
The solution is to have the torque converter replaced and the transmission serviced.
Hopefully, you are still under warranty and can get it repaired it for free.
If not, it can get pretty expensive.