From June 5 to June 11 SunPass will be updating thier systems. You may still use your transponders to pay for tolls during the system maintenance period. However, you won't be able to add money to your account during that period.
In addition, SunPass Plus at Palm Beach International Airport and most other Florida airports will be shut down. You won't be able to pay using your SunPass transponder. You will have to pay with cash or credit card.