A safety guardian is operable to facilitate notifying an Electronic Vehicle Supply Equipment (EVSE) system whether a vehicle charging system is ready to accept energy. The safety guardian may be configured to facilitate control of a vehicle interface used to provide a reference voltage to the EVSE reflective of whether the charging system is ready to accept energy. The guardian may control the vehicle interface in the absence of a suitable control signal from the vehicle charging system in order to ensure the EVSE is notified when the vehicle charging system is not ready to accept energy.