Bulletin No.: 24-NA-160

Service Bulletin

Date: August, 2024

TECHNICAL
Subject:

Brand:

Chevrolet

Malfunction Indicator Lamp (MIL) Illuminated - DTC P0A7B and/or P0E3C
Set

Model:

Corvette ERay

Model Year:

Build Date:

from

to

from

to

2024

2025

—

—

Engine:

Transmission:

6.2L (LT2)

8–Speed Dual
Clutch (MLH)

Involved Region or Country

North America, Europe, Middle East, Japan, Australia/New Zealand

Additional Options (RPOs)

HP1 (ELECTRIFIED PROPULS - ELECTRIC, ELECTRIC AXLE FRT, SPORT)

Condition

Some customers may comment that the MIL is illuminated.
Technicians may find one or more of the following DTCs set:
• P0A7B set in the K20 ECM
• P0E3C set in the K16 Battery Energy Control Module
Important: If any other DTCs set for battery pump diagnostics or loss of isolation diagnostics, follow SI for those codes. This bulletin does not apply to that condition.

Cause

This condition may be caused by air gathering and getting trapped in the hoses around
the Hybrid/Electric Vehicle Battery Coolant Pump from a previous repair. This causes the
pump to stop for self-protection, and the BECM interprets that as an under-speed condition.

Correction

Refer to the Service Procedure to aid in purging the trapped air.

Important: Service agents must comply with all International, Federal, State, Provincial, and/or Local laws
applicable to the activities it performs under this bulletin, including but not limited to handling, deploying,
preparing, classifying, packaging, marking, labeling, and shipping dangerous goods. In the event of a
conflict between the procedures set forth in this bulletin and the laws that apply to your dealership, you
must follow those applicable laws.

Service Procedure
1. Remove the Front Compartment Rear Access Cover. Refer to Front Compartment Rear Access Cover
Replacement.
2. Remove the Underbody Rear Air Deflector. Refer to Underbody Rear Air Deflector Replacement.
− The pump in question is on the lower left side of the engine bay.
3. Carefully slide the pump inboard out of its mount and hang it low relative to the other plumbing without kinking
the hoses.
4. Lower the vehicle.

Copyright 2024 General Motors. All Rights Reserved.

Page 2

August, 2024

Bulletin No.: 24-NA-160

6660034

5. In the engine compartment, rotate the high voltage battery coolant (RESS) surge tank cap upper cover (1)
counterclockwise to align the slot (3) in the cap cover with the slot in the cap body (2).
6. Insert a suitable flat-bladed tool into the slot, no wider than 8 mm (5/16”).
7. With the cap sections engaged, rotate the high voltage battery coolant (RESS) surge tank cap counterclockwise
by hand to loosen and remove.
8. To maintain battery voltage, connect a battery charger. Refer to Battery Charging in SI.
8.1.

Connect the 12-volt lithium-Ion battery to a 13.5-volt power supply.

8.2.

Use a power supply that is greater than 13.5-volts and 27.7-amps continuous to ensure the battery is not
discharging.
9. Place the vehicle in Service Mode.
10. Using TLC/GDS 2, run the hybrid/electric vehicle battery coolant pump (RESS) 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.

− Repeat steps 9 & 10 as needed to purge air from system.
− For reference, the total system volume is 1.9 L.
11. Install the (RESS) high voltage battery coolant loop surge tank cap.
12. Remove battery charger.
13. Install the Front Compartment Rear Access Cover. Refer to Front Compartment Rear Access Cover
Replacement.
14. Raise the vehicle.
15. Carefully slide the G65 pump back into its mount.
16. Visually check the cooling system for leaks.

Bulletin No.: 24-NA-160

August, 2024

Page 3

17. Install the Underbody Rear Air Deflector. Refer to Underbody Rear Air Deflector Replacement.
18. Clear DTCs using TLC/GDS2.
19. Turn off the vehicle.
Note: If the DTC P0E3C sets again after 2 or more purges, follow regular SI diagnostics for the pump.

Warranty Information
For vehicles repaired under the Bumper-to-Bumper coverage (Canada Base Warranty coverage), use the following
labor operation. Reference the Applicable Warranties section of Investigate Vehicle History (IVH) for coverage information.
Labor Operation

Description

Labor Time

5086028*

Purge Entrapped Air from
Battery Cooling System

1.0 hr

*This is a unique Labor Operation for bulletin use only.
Version

1

Modified

Released August 14, 2024

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these
technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper
service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job
properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your
vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the
information.

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