As far as for changing it yourself, its not really an option, unless you wanted to pay for it yourself. Warranty will not cover a part unless it is installed by the dealer. One of the many hoops the dealer has to go through to get the part covered under warranty.
The problem could be in these few things
Short in the actuator circut
Blown BK/Hn/Mflr
Short in brake light or horn circuts.
Physical problem with the actuator or cable.
Check out those few things and let me know what the problematic item is on your bike.
I checked all the current recalls/service bulletins and came up with nothing involving the exhaust servo, so you're safe there.
Need any further info, just hit me up