Battery voltage too high ?!

Evening people ;D I have the following problem with my Ducati Monster 695 Bj 2006: The good one has only driven 4000 kilometers but has stood for it a lot, so much to the bike. Now my problem. I start the motorcycle and come with the speed (whether idling or under load) on something over 1500 revolutions the motor control light goes on, let it run in idle run the lamp off. Now I was with a colleague who has read out the error the is battery voltage to High. Only when I measure at the battery everything is top. But I leave it on the voltage goes to 15 V. Now I have removed the controller and see the error disappears. So new controllers ordered, built in and still the same Sch****. Would be grateful for every tip ;D LG Dominik