PITSTOP: ?FILL INVERTER COOLANT? MESSAGE AFTER REPAIR - Some technicians may report seeing the ?fill inverter coolant? message on the cluster after performing an HEV system service requiring the coolant to be drained. The logic for this message is such that it will be displayed when the RPM of the EWP climbs while line load goes down, indicating a possible cavitation. This is due to air in the system. Much like bleeding any fluid system utilizing a pump, the hybrid cooling system must be bled in a particular manner to avoid aeration.
