Tell your dealer to get off their lazy asses and help you.
A full system will not void any warranty. IF you have a PC on it they will want you to remove it--or unplug it--before they attempt to work on it.
Just because the "test" in the GS911 says "do you hear the injector ticking" doesn't necessarily mean it is working all the time. Does the GS say how many times it has occurred? If you decide to check under the tank check all the zip tied wiring to the injector rail. I've seen several times where the zip-ties are put on so tight that it damages a wire. Not on the S but on other BMRs.