I found this on an american forum, can’t remember where. It doesn’t address your problem but it may have some tips you can use.
First turn on the Sena by pressing and holding the Jog Dial button (in the center of the Jog Dial) while you're also holding down the Phone Button (the one on the rear of the unit). You'll get a slow blinking blue light. It's now turned on.
Then put the SRC into phone pairing mode by pressing and holding down the "Mobile" button. That's the one between the two raised posts. When it turns on you'll get a slow blue blink from the buttons adjacent to the Mobile button. Then press and hold the Mobile button again, this time for about 6 seconds. When the lights change to a rapid red−blue−red−blue you're there.
Then you're going to put the Sena into "Universal Intercom Pairing mode." Up until this point, all the Techies had me putting BOTH devices into phone pairing mode and that's why nothing was happening.
Press the Jog Dial and hold it down (NOT the Jog Dial Button, but the dial itself) for 12 seconds. It may go through other modes, mine started playing music from my phone that it was linked to, but keep holding the dial down. You'll hear a beep after 12 seconds. Release the button and you'll hear the Sena say something like "Entering Configuration Mode."
Then turn the Jog dial clockwise until it beeps, it doesn’t take much, it will announce the name of the new menu item. Keep turning the dial clockwise a little at a time, until you get to "Universal Intercom Pairing." (NOTE: I think that you can turn the dial counterclockwise and get to this setting a little faster).
Your SRC will announce, "Phone paired" (or something along those lines). The red−blue−red−blue rapidly flashing lights alongside the Mobile button on the SRC will stop flashing and go back to the slow blue blink.
Hope there is something here that helps.
Tom