Kia Optima Hybrid 2017 — technical service bulletin
Bulletin PS508 · NHTSA communication 10116108 · issued Jun 19, 2017
Technical service bulletin
communication type
Engine and Engine Cooling
component
2017
model years
1
vehicle entries
Official summary
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.
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.