GENERAL MOTORS
DCS 7309
URGENT - DISTRIBUTE IMMEDIATELY
Date:

August 27, 2025

Subject: REVISION: N252510321-01 - Service Update
ECM Software Update
Expanded Population
Models: 2021-2023 Cadillac Escalade
2021-2023 Cadillac Escalade ESV
2021-2024 Chevrolet Silverado 1500
2021-2023 Chevrolet Suburban
2021-2023 Chevrolet Tahoe
2021-2024 GMC Sierra 1500
2021-2023 GMC Yukon
2021-2023 GMC Yukon XL
This bulletin is being revised to include 2021 Full-size SUVs. Please discard all
previous copies of bulletin N252510321.
This is a phased launch.
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.
To identify involved vehicles in dealer used inventory, run an Open VIN Report
or Field Action Initiation Report using Field Action Reports-GFAM within the
Maxis Dealer Application in Global Connect.
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
N252510321 ECM Software Update
Release Date:
Revision Description:

Attention:

August 2025

Revision:

01

This bulletin has been revised to include 2021 Full-size SUVs. Please discard all
previous copies of bulletin N252510321.

This service update includes vehicles in dealer inventory and customer vehicles that return to the
dealership for any reason.
This is a phased launch.
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.
2023 and 2024 Model Year vehicles only: 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
Cadillac
Chevrolet
Chevrolet
Chevrolet
GMC
GMC
GMC

Model
Escalade
Escalade ESV
Silverado 1500
Suburban
Tahoe
Sierra 1500
Yukon
Yukon XL

From
2021
2021
2021
2021
2021
2021
2021
2021

To
2023
2023
2024
2023
2023
2024
2023
2023

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 will receive a software update to add to the existing Check Engine Light a
Driver Information Center (DIC) warning message if DTC P0016 sets.
Dealers will reprogram the Engine Control Module (ECM). 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
9107809*

9107810*

Description
Verified Module Software or Calibration Level: Module Is
Programmed with Same Level Software or Calibration
Engine Control Module Reprogramming with SPS
MY21, MY22 with RPO J21
MY22 with RPO J22
MY23+

Labor
Time

Trans.
Type

Net
Item

ZFAT

N/A

0.2
0.3
0.4
0.4

Please Note: The above labor time(s) are published direct from the Labor Time Guide.
Important:

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

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Service Update
N252510321 ECM Software Update

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
Caution: Before downloading the update files, be sure the computer is connected to the internet through a network cable
(hardwired). DO NOT DOWNLOAD or install the files wirelessly. If there is an interruption during programming,
programming failure or control module damage may occur.
Note: Carefully read and follow the instructions below.
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Service Update
N252510321 ECM Software Update
•

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.

•

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.

•

Please verify that the radio time and date are set correctly before inserting USB drive into vehicle for programming,
otherwise an error will result.

•

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 Engine Control Module (ECM) is the primary module (for VIP ICE 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 ECM also
needs to be reprogrammed with the correct VIN, software and calibrations that match the vehicle’s VIN plate.

•

The Body Control Module (BCM) is the primary module (for GEM 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.

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Service Update
N252510321 ECM Software Update

5877000

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 Engine Control Module. Refer to K20 Engine 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.

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Service Update
N252510321 ECM Software Update
Dealer Responsibility
Whenever a vehicle subject to this service update enters your vehicle inventory or is in your facility for service in the
future, 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.
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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