I am trying to pair my iphone 4 with my 2007 bmw bluetooth. the phone recognizes the bluetooth but when I enter the code it says pairing unsuccessful. How do I make it pair

Give or take which iOS you're running:

1. Go to Settings > Bluetooth. Should be the third thing from the top, under Airplane Mode and Wi-Fi. Enter the Bluetooth section.
2. Depending on what you're pairing with, read the instructions. Some devices will have a bluetooth pairing code that they will need to be sent back to them from your phone. Others will do it ad-hoc.
3. Turn on the other device and put it into bluetooth pairing mode. Turn on Bluetooth on your phone. Be close to the other device, preferably within a few feet.
4. If prompted, enter the handshaking code into your phone - it'll prompt you for a code if the handshake goes that way. it may see a number of bluetooth devices to pair with, in which case you'll start by picking the one that you're trying to pair with. Then, if needed, you'll be talked through it.
5. that's about it for an iPhone. If you have trouble pairing to anything, this can mean that the radio chip is having issues. this will arise in particular if you've had any WiFi connection issues as well.
   
   Good Luck

Try this - http://www.wikihow.com/Pair-Your-Bluetooth-Phone-With-a-2006-2009-Bmw-3-Series

did you mean via bluetooth? if yes please remove saved car kit devices from you phone and then try again with correct pass-codes

Key-in, Ignition On (but don't need to start the engine)Press the R/T button on the steering wheel. "Activate Phone" should display on the radio. On the iPhone search the BT device. Select your car and enter the passkey when prompt on the iphone. Make sure there is no other BT phone near-by or the old one that has paired with the car previously. There is also the maximum number of devices you can have in the BMW BT sharing. If you reach the max, you may have to clear the car BT pairing memory by removing the power to the BT unit (by removing a fuse in the rear fuse box). The info is in the manual and inside the fuse box (which tell you which fuse is for the BT.)

make sure that the code you enter in to the phone as the pairing code is correct. most of them are 0000 or 00000, some of the samsungs are 1234.

this code must be entered in correctly to pair the device. If you are using an iphone, there are some issues with it people report.

The reason is you need a four digit code in order to pair your Bluetooth to your phone. Also, your phone has to be 'Able to be found', ie, set your Bluetooth settings on your phone, so that the phone is in 'Discoverable Mode' and ensure the Bluetooth setting itself is also turned on.

Once your phone is Bluetooth discoverable, try and pair the devices again. Your phone will find your headset and ask if you would like to pair the two devices. Obviously, select Yes/Pair and it will then require a 4 digit code for authentication. With Jabra the code is always "0000" (4 zero's). Once you enter the 4 zero's, the two units will then pair successfully.

Let me know if you require further assistance.

You have to search the device from your phone and enter the passcode when it is detected.
Make sure you have enter the correct pairing code and your phone has bluetooth 2.0.

some phones do not work with the bmw systems please check with your dealer which phone works on your model

Turn bluetooth on by settings-general-bluetooth. this will make it discoverable, follow direction with device you wish to connect, the iphone should recognize it when you turn it on, it will ask you for a pairing code. Enter that and it should connect.

I have a new acura that I paired with mine the instruction were in the manual for the car. You have to set your car up and enter a code. Turn on bluetooth on your phone hit setting-general-bluetooth and this will make you iphone visible to your car when your setting it up. When they find each other your phone should pop up with a question to pair enter code. That is really all there is to it.