GLOBAL SAFETY FIELD INVESTIGATIONS
DCS6736
URGENT - DISTRIBUTE IMMEDIATELY
Date:

December 6, 2023

Subject: N232412720 – Service Update
ECM Communications to Emissions Test Tools
Models: 2024 Chevrolet Silverado 2500 HD/3500 HD
2024 GMC Sierra 2500 HD/3500 HD
To:

All General Motors Dealers

General Motors is releasing Service Update N232412720 today. The total
number of U.S. vehicles involved is approximately 62,144. Please see the
attached bulletin for details.
Global Warranty Management (GWM)
The Required Field Action section on the Investigate Vehicle History (IVH) screen will
be updated December 6, 2023. A list of vehicles in dealer inventory is attached to this
message.
END OF MESSAGE
GLOBAL SAFETY FIELD INVESTIGATIONS

Service Update
N232412720 ECM Communications to Emissions Test Tools
Release Date:
Attention:

December 2023

Revision:

00

This service update includes vehicles in dealer inventory and customer vehicles that return to the
dealership for any reason.
All involved vehicles in the US and Canada that are in dealer inventory must be held and not delivered
to customers, dealer traded, or used for demonstration purposes until the repair contained in this bulletin
has been performed on the vehicle.
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.

Make
Chevrolet
GMC

Model
Silverado 2500 HD/3500 HD
Sierra 2500 HD/3500 HD

Model Year
From
To
2024

RPO

Description

2024

Involved vehicles are marked “Open” on the Investigate Vehicle History screen in GM Global Warranty Management
system. This site should always be checked to confirm vehicle involvement prior to beginning any required inspections
and/or repairs.
Condition

Correction

Certain 2024 model year Chevrolet Silverado 2500 HD/3500 HD and GMC Sierra 2500 HD/3500 HD
vehicles, with a 6.6L diesel engine, may have an Engine Control Module (ECM) that does not correctly
provide all required data to emissions Inspection/Maintenance (I/M) testing stations. Additionally, if the
brake system control module would detect certain faults, the ECM may not properly illuminate the
Malfunction Indicator Lamp (Check Engine Light). Dashboard warning messages and warning lights for
traction control, stability control, and brake system remain functional for such faults.
Dealers are to reprogram the ECM and TCM.

Parts
No parts are required for this repair.
Warranty Information
Labor
Operation
9106853*
9106854*
Important:

Description
Verified Module Software or Calibration Level: Module Is
Programmed with Same Level Software or Calibration
Sequential ECM/TCM Module Reprogramming with SPS

Labor
Time
0.2

Trans.
Type

Net
Item

ZFAT

N/A

0.7

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

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

Copyright 2023 General Motors. All Rights Reserved.

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Service Update
N232412720 ECM Communications to Emissions Test Tools
“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.

•

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.

•

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.

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Service Update
N232412720 ECM Communications to Emissions Test Tools
•

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 master module (for VIP 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 master 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.

5877000

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Service Update
N232412720 ECM Communications to Emissions Test Tools

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 ECM and TCM Control Modules using a sequential programming event in SPS2.

6404112

2.

Select K20K71 – Engine and Transmission Control Module as shown on the Selected Controllers screen and proceed
with programming. Follow all instructional pop-ups in SPS2.
2.1 After reprogramming, perform the following steps in GDS2.
2.2 Select: Module Diagnostics.
2.3 Select: Engine Control Module.
2.4 Select: Configuration/Reset Functions.
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Service Update
N232412720 ECM Communications to Emissions Test Tools
2.5 Select: Reset Functions.
2.6 Select: BARO Sensor Reset.
2.7 Follow the instructions on the scan tool.

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.
3.

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

Dealer Responsibility
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.
Dealers are to service all vehicles subject to this service update at no charge to customers, regardless of mileage, age of
vehicle, or ownership, from this time forward.
In summary, whenever a vehicle subject to this service update enters your vehicle inventory you must take the steps
necessary to ensure the program correction has been made before selling the vehicle. In addition, for vehicles entering
your facility for service, you are required to ensure the customer is aware of the open field action and make every
reasonable effort to implement the program correction as set forth in this bulletin prior to releasing the vehicle.
Dealer Reports – For USA & 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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