GENERAL MOTORS
DCS7346
URGENT - DISTRIBUTE IMMEDIATELY
Date:

October 16, 2025

Subject: N232401570 - Service Update
Cell Monitoring Unit Offline
Models: 2023-2024 Cadillac LYRIQ
2023-2024 Chevrolet BrightDrop 600
2023-2024 Chevrolet BrightDrop 400
2024 Chevrolet Blazer EV
2024 Chevrolet Silverado EV
2022-2024 GMC HUMMER EV

General Motors is releasing Service Update N232401570 today.

What Should Dealers Do: Dealers should review IVH, or the Dealer Maxis reports
for open VINs in their inventory. Dealers can view the attached bulletin, and it
will also be displayed in Service Information tomorrow.
The Stock VIN list of vehicles in dealer inventory is attached to this message.
Note: this list is only accurate at the time of report creation and all VINs should
be validated in IVH prior to repair.
The Inventory tab of the Open Vehicle Report will contain Service Update Bulletin
VINs that apply to this field action. This information is intended to assist dealers
with the PROMPT COMPLETION of these vehicles. The Customer In-Service
tab will not contain Service Update Bulletin VIN data because the intent of a
Service Update Bulletin is to not inconvenience a customer with a special trip for
service. Service Update Bulletins are to be completed when the customer is in
for a regularly scheduled visit.
END OF MESSAGE

Service Update
N232401570 Cell Monitoring Unit Offline
Release Date:
Attention:

October 2025

Revision:

00

This service update includes vehicles in dealer inventory and customer vehicles that return to the
dealership for any reason. This bulletin will expire October 31, 2027.
For EV Involved Vehicles: The repairs outlined in this bulletin must only be completed at an authorized
EV dealer and repairs must be performed by a technician who has successfully completed the
applicable technical training required to perform this repair.
Investigate Vehicle History (IVH) in the GM Global Warranty Management system MUST always
be checked to confirm vehicle involvement and MUST be in OPEN status prior to beginning any
required inspections and/or repairs. DO NOT use Service Information with VIN search, as it will
not verify the VIN eligibility for field actions.
Involved vehicles will be repaired either through dealer repairs as described in this bulletin or through
over the air (OTA) programming. Dealers can and should perform the procedure in this bulletin on any
vehicle with an “open” status on the Investigate Vehicle History (IVH) screen in GM Global Warranty
Management system. Due to the fact that vehicles will be closed in IVH through successful OTA
programming, dealers should always check the status in IVH before performing any vehicle repairs.
Refer to Technical Service Bulletin 21-NA-043 for properly maintaining vehicles in dealer inventory.
Model Year

Make
Cadillac
Chevrolet
Chevrolet
Chevrolet
Chevrolet
GMC

Model
LYRIQ
BrightDrop 600
BrightDrop 400
Blazer EV
Silverado EV
HUMMER EV

From
2023
2023
2024
2024
2024
2022

To
2024
2024
2024
2024
2024
2024

Investigate Vehicle History (IVH) in the GM Global Warranty Management system MUST always be checked to confirm
vehicle involvement and MUST be in OPEN status prior to beginning any required inspections and/or repairs. DO NOT
use Service Information with VIN search, as it will not verify the VIN eligibility for field actions.
Condition
Correction

Certain vehicles listed above may have a condition in which the Battery Energy Control Module will not
exit “commissioning” (start-up), because a Cell Monitoring Unit is offline.
Dealers will reprogram the Battery Energy Control Module. Owners who have accepted applicable terms
and conditions will have the opportunity to accept these software changes using wireless over-the-air
(OTA) technology without having to bring their vehicle to a dealership. Alternatively, owners may have
their vehicle serviced at a GM dealer to receive these software updates.

Parts
No parts are required for this repair.
Warranty Information
Labor
Operation
9107829*
9107830*
Important:

Description
Verified Module Software or Calibration Level: Module Is
Programmed with Same Level Software or Calibration
Battery Energy Control Module Reprogramming with SPS

Labor
Time
0.2

Trans.
Type

Net
Item

ZFAT

N/A

0.3

* To avoid warranty transaction rejections, carefully read and follow the instructions below:

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Service Update
N232401570 Cell Monitoring Unit Offline

6125814

• The Warranty Claim Code from the programming event must be accurately entered in the “Warranty Claim
Code” field of the transaction.
•

When more than one Warranty Claim Code is generated for a programming event, it is required to document all
Warranty Claim Codes in the “Correction” field on the job card. Dealers must also enter one of the codes in the
“Warranty Claim Code” field of the transaction, otherwise the transaction will reject. It is best practice to enter
the FINAL code provided by SPS2.

Warranty Claim Code Information Retrieval

6125774

If the Warranty Claim Code was not recorded on the Job Card, the code can be retrieved in the SPS2 system as
follows:
1.
2.
3.
4.

Open TLC on the computer used to program the vehicle.
Select and start SPS2.
Select Settings (1).
Select the Warranty Claim Code tab (2).

The VIN, Warranty Claim Code and Date/Time will be listed on a roster of recent programming events. If the code is
retrievable, dealers should resubmit the transaction making sure to include the code in the SPS Warranty Claim Code
field.
Service Procedure
Note: Carefully read and follow the instructions below.

•

Ensure the programming tool is equipped with the latest software and is securely connected to the data link connector.
If there is an interruption during programming, programming failure or control module damage may occur.

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Service Update
N232401570 Cell Monitoring Unit Offline
•

Stable battery voltage is critical during programming. Any fluctuation, spiking, over voltage or loss of voltage will
interrupt programming. Install a GM Authorized Programming Support Tool to maintain system voltage. Refer to
www.gmdesolutions.com for further information. If not available, connect a fully charged 12 V jumper or booster
pack disconnected from the AC voltage supply. DO NOT connect a battery charger.

•

Follow the on-screen prompts regarding ignition power mode, but ensure that anything that drains excessive power
(exterior lights, HVAC blower motor, etc) is off.

•

Clear DTCs after programming is complete. Clearing powertrain DTCs will set the Inspection/Maintenance (I/M)
system status indicators to NO.

Important: The service technician always needs to verify that the VIN displayed in the TLC left side drop down menu and
the top center window match the VIN plate of the vehicle to be programmed prior to using Service Programming System
2 (SPS2) for programming or reprogramming a module.

•

For the TLC application, service technicians need to always ensure that the power mode (ignition) is “ON” before
reading the VIN from the vehicle’s VIN master module and that they do not select a VIN that is already in the TLC
application memory from a previous vehicle.

•

If the VIN that shows up in the TLC top center window after correctly reading the VIN from the vehicle does not match
the VIN plate of the vehicle, manually type in the VIN characters from the vehicle VIN plate into the TLC top center
window and use these for programming or reprogramming the subject module with the correct vehicle VIN and
software and/or calibrations.

•

The Body Control Module (BCM) is the primary module (for VIP EV vehicles) that TLC reads to determine the VIN of
the vehicle. If the VIN read from the vehicle by TLC does not match the VIN plate of the vehicle, the BCM also needs
to be reprogrammed with the correct VIN, software and calibrations that match the vehicle’s VIN plate.

Caution: Be sure the VIN selected in the drop down menu (1) is the same as the vehicle connected (2) before beginning
programming.

5743643

Important: If the vehicle VIN DOES NOT match, the message below will be shown.

5877000

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Service Update
N232401570 Cell Monitoring Unit Offline

5644477

Important: Techline Connect screens shown above.
Important: If the same calibration/software warning is noted on the TLC Summary screen, select OK and follow
screen instructions. After a successful programming event, the WCC is located in the Service Programming System
dialogue box of the SPS Summary screen. No further action is required. Refer to the Warranty section of the bulletin.
1.

Reprogram the Battery Energy Control Module. Refer to K16 Battery Energy Control Module: Programming and Setup
in SI.

5644478

Note: The screenshot above is an example of module programming and may not be indicative of the specific module
that is being programmed. Module selection and VIN information have been blacked out.
Important: To avoid warranty transaction rejections, you MUST record the warranty claim code provided on the
Warranty Claim Code (WCC) screen shown above on the job card. Refer to callout 1 above for the location of the
WCC on the screen.
2.

Record SPS Warranty Claim Code on job card for warranty transaction submission.

Dealer Responsibility
Whenever a vehicle subject to this service update enters your vehicle inventory or is in your facility for service through
the end date as noted in the Attention box, you must take the steps necessary to be sure the service update correction
has been made before selling or releasing the vehicle.
All new, used, GM Certified Pre-Owned (CPO), courtesy transportation vehicles, dealer shuttle vehicles, CarBravo, etc.
in dealers' possession and subject to this field action must be held and inspected/repaired per the service procedure of
this bulletin before customers take possession of these vehicles. Involved vehicles must be held and not delivered to
customers, dealer-traded, released to auction, used for demonstration, or any other purpose.
All GM Certified Pre-Owned (CPO) vehicles currently in the dealers’ inventory within the SHIFT Digital system will be
de-certified and must be held and remedied per the service procedure in this bulletin. Upon submitting an accepted/paid
warranty transaction in the Global Warranty Management (GWM) system, the vehicle can be re-certified for sale within
the SHIFT Digital system, or once again be used in the Courtesy Transportation Program.
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Service Update
N232401570 Cell Monitoring Unit Offline
Dealer Reports – For USA and Export
The Inventory tab of the Open Vehicle Report will contain Service Update Bulletin VINs that apply to this field action.
This information is intended to assist dealers with the PROMPT COMPLETION of these vehicles. The Customer InService tab will not contain Service Update Bulletin VIN data because the intent of a Service Update Bulletin is to not
inconvenience a customer with a special trip for service. Service Update Bulletins are to be completed when the
customer is in for a regularly scheduled visit.

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 tools, equipment, 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 dealer for information on whether your
vehicle may benefit from the information.

We Support
Voluntary Technician
Certification

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