The 2024-2025 Corvette E-Ray features an independent cooling system to cool the high-voltage battery. If air gathers and gets trapped in the hoses around the Hybrid/Electric Vehicle Battery Coolant Pump (Fig. 9, #5) during repairs,
it can cause the pump to stop for self-protection, which the Battery Energy Control Module (BECM) interprets as an under-speed condition. DTC P0E3C (Hybrid/Electric Vehicle Battery Pack Coolant Pump Underspeed) may set in the BECM and DTC P0A7B (Battery Energy Control Module Requested Malfunction Indicator Lamp Illumination) may set in the Engine Control Module (ECM). The air trapped in the system must be purged.

TIP: If any other DTCs set related to the battery pump or loss of isolation, follow the appropriate Service Information diagnostics for those DTCs.
To purge the pump, begin by removing the Front Compartment Rear Access Cover and the Underbody Rear Air Deflector.
The G65 Hybrid/Electric Vehicle Battery Coolant Pump is on the lower-left side of the engine bay. The pump will need to be slid inboard out of its mount and lowered relative to the other plumbing without kinking the hoses.

In the engine compartment, rotate the high-voltage battery coolant (RESS) surge tank cap upper cover (Fig. 10, #1) counterclockwise to align the slot in the cap cover (Fig. 10, #3) with the slot in the cap body. (Fig. 10, #2) Insert a suitable flat-bladed tool into the slot and, with the cap sections engaged, rotate the surge tank cap counterclockwise to remove it. Do not use the flat-bladed tool to loosen the cap.

To maintain battery voltage, connect a battery charger, and then place the vehicle in Service Mode.

Use GDS 2 to run the Hybrid/Electric Vehicle Battery Coolant Pump (Fig. 11) at 4,000 RPM for 15 minutes. If the coolant level drops, fill the cooling system using DexCool 50/50 Premix. The coolant level should just cover the white indicator at the bottom of the small coolant reservoir. For reference, the total system volume is 1.9 L. Run the pump again if needed to purge all air from the system.

If DTC P0E3C sets again after two or more purges, follow the appropriate Service Information diagnostics for the pump.
For more details, refer to Bulletin #24-NA-160.