Could be a few reasons for this one, most likely an open circuit. Check all your electrical plastic plugs and make sure all are fitted properly to the sensors they plug into. you may even like to go to the trouble of unplugging then re fitting every plug. Then when your happy everything is connected properly, do a fault code test to see what the F1 system is saying. i bet you havnt re connected the air temp sensor, which is fitted to the right hand lower side of your air box. Safe riding to all from Kev