The issue stems from the air in the battery’s cooling circuit, as some batteries were not filled with the proper amount of cooling air during the manufacturing process. The batteries are supposed to purge any air from the system over the first year on the road, but the process leaves less coolant than is required in some cases.
If the coolant becomes too low, the Volt’s trip computer on the dashboard will display a “Service High-Voltage Charging System” warning. If this happens, the Volt’s charging system will be disabled until the necessary service is complete.
GM is not issuing a formal recall over the matter and is instead asking customers to make appointments with the service bay at their local Chevrolet dealer. Dealers will check the level of coolant air in the battery and will add coolant pressure if it is found to be too low. They will also test the system for leaks, but those repairs will only be free of charge if the car is still under warranty.
Volt owners can call their local dealer, who will search the cars VIN to see if it needs to be fixed. They may also contact Chevrolet at 1-866-694-6546.