REMEMBER the phone gets to do the pairing not the radio. Turn radio on and make sure you are close enough to synk. Place the phone in pairing mode and see if it can pull up the radio by showing it on the screen. Sometime it might show as a unfamiliar name , so look closely to see if there is one you do not regonize. If you don't see the radio, turn it off and on a few times while the phone is in pairing mode.
Hope this helps. This is a general way to pair and not at all the only way. If you cannot pair after this contact the radio and phone manufactiure to make sure they are compatible.