GLOBAL SAFETY FIELD INVESTIGATIONS
DCS6745
URGENT - DISTRIBUTE IMMEDIATELY
Date:

December 13, 2023

Subject: N232427140 - Customer Satisfaction Program
Tire Size Reprogramming
Models: 2022 – 2023 Chevrolet 6500XD LCF
To:

All General Motors Medium Duty Dealers

General Motors is releasing Customer Satisfaction Program N232427140
today. The total number of U.S. vehicles involved is approximately 171.
Please see the attached bulletin for details.
Customer Letter Mailing
The customer letter mailing will begin in the near future.
Global Warranty Management (GWM)
The Required Field Action section on the Investigate Vehicle History (IVH) screen will
be updated December 13, 2023. A Stock VIN list is not included as our records show
there are no vehicles in dealer new inventory.
END OF MESSAGE
GLOBAL SAFETY FIELD INVESTIGATIONS

Customer Satisfaction Program
N232427140 Tire Size Reprogramming
Release Date:
Attention:

December 2023

Revision:

00

ONLY Chevrolet Medium Duty dealers can complete this field action repair.
This program is in effect until January 31, 2026.

Make
Chevrolet

Model
6500XD LCF

Model Year
From
To
2022
2023

RPO

Description

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 2022 - 2023 model year Chevrolet 6500XD Medium Duty LCF vehicles, equipped with tire size
255/70R22.5 may have a calibration error where the vehicles were built with an incorrect tire size value.
As a results, the speedometer will show a vehicle speed higher than the actual vehicle speed while
driving and the odometer will accumulate miles faster (approximately 14% faster) than the “actual” or
“True” vehicle miles. Additionally, mileage data collected and stored in the Mimamori Unit (MMU), will be
incorrect.
Dealer will have the Cummins Engine Control Module (ECM) reprogrammed with the correct tire size
value and reprogram the MMU.

Parts
No parts are required for this repair.
Warranty Information
Labor
Operation
9107098

9107041*

Description
Base: Reprogram ECM (Schedule / Coordination with Cummins
Service Location)
Tire size matches GDS2 Tire Value, No MMU reprogramming
needed
Base: Reprogram ECM (Schedule / Coordination with Cummins
Service Location)
Add: Reprogram MMU

Labor
Time
0.5

Trans.
Type
ZFAT

Net
Item
N/A

ZFAT

N/A

0.2
0.5
0.4

Service Procedure
1.

2.

3.

Physically inspect the vehicle’s tires and record the tire’s size value. The tire size should be 255/70R22.5.
•

If the tire size IS NOT 255/70R22.5, contact the GM Technical Assistance Center at 877-446-8227 for further
assistance.

•

If the tire size IS 255/70R22.5, continue to the next step.

Contact the local Cummins Certified Service location to have the ECM reprogrammed per the procedure below.
•

If you (the dealer) are also a Cummins Certified Service location, this procedure should be performed at your
location, as you are the closest Cummins Certified Service location.

•

If you (the dealer) are not a Cummins Certified Service location, you should arrange to have this procedure
performed at the closest Cummins Certified Service location; you can find the closest Cummins Certified Service
location on the web at https://www.cummins.com/locations.

Provide the “Procedure” section of this bulletin to the Cummins location to have a Cummins trained technician
reprogram the ECM with the correct Tire Size value settings using the Cummins INSITE tool.

Important: Once the Cummins procedure is completed, proceed to “MMU Configuration”.
Procedure (To be completed by a Cummins Certified Service Location Using INSITE)

Copyright 2023 General Motors. All Rights Reserved.

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Customer Satisfaction Program
N232427140 Tire Size Reprogramming

6472130

4.

Using the Cummins INSITE tool (version 8.8.0.101 or later), from the Main Screen, select “Connect to ECM” to
establish communication with ECM, and select “Connect”.

6472131

5.

Navigate to “Features and Parameters”.

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Customer Satisfaction Program
N232427140 Tire Size Reprogramming

6472072

6.

Navigate to “Vehicle Speed Source”.

6472073

7.

Navigate to “Tire Size.”

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Customer Satisfaction Program
N232427140 Tire Size Reprogramming

6472074

8.

Change the Tire Size calibration from 491 rev/miles to 563 revs/mile (low profile tire size value).

6472075

9.

Navigate to “File”, select “Send To”, and select “ECM”.

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Customer Satisfaction Program
N232427140 Tire Size Reprogramming

6472076

10. Click OK to confirm ECM adjustment.

6472077

11. Turn the Key Switch off and click OK.

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Customer Satisfaction Program
N232427140 Tire Size Reprogramming

6472078

12. Wait for the progress bar to complete.

6472079

13. Turn the Key Switch on and click OK.

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Customer Satisfaction Program
N232427140 Tire Size Reprogramming

6472080

14. The corrected value will show stored in the ECM. Confirm corrected “Tire Size” ECM Value.
15. Once the ECM has been reprogrammed, proceed to “MMU Configuration.”
Important: To avoid warranty transaction rejections, ensure that the Cummins Repair order number is correctly added
in the “Document ID” field.

6496858

16. In GWM, submit the Cummins Repair Order Number in the “Document ID” field.
MMU Configuration
Important: * To avoid warranty transaction rejections, carefully read and follow the instructions below:

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Customer Satisfaction Program
N232427140 Tire Size Reprogramming

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. Open TLC on the computer used to program the vehicle.
2. Select and start SPS2.
3. Select Settings (1).
4. 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 for MMU Reprogramming

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Customer Satisfaction Program
N232427140 Tire Size Reprogramming

6495260

1.

To check current Tire Size value, go to GDS2, select “Module Diagnostics.” Press “Enter.”

2.

Select “Mimamori ECU.” Press “Enter.”

6495261

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Customer Satisfaction Program
N232427140 Tire Size Reprogramming

6495262

3.

Select “Identification Information.” Press “Enter.”

6495263

4.

Select “Configuration Data.” Press “Enter.”

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Customer Satisfaction Program
N232427140 Tire Size Reprogramming

6495265

5.
•

•

Scroll down the Parameter Names until you find “Tire Size.” Verify that the tire size is 255/70R22.5 under the
“Value” row.
If the value that was recorded in the inspection conducted in Step 2 is 255/70R22.5 and the MMU value is
255/70R22.5, the tire size value is CORRECT. No further action is required.
If the value that was recorded in the inspection conducted in Step 2 is 255/70R22.5 and the MMU is 11R22.5, the
tire size value is INCORRECT. Continue to the next step to configure the correct tire value.

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.

•

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.

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Customer Satisfaction Program
N232427140 Tire Size Reprogramming
•

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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Customer Satisfaction Program
N232427140 Tire Size Reprogramming

6496849

6.

At this screen, select MMU under “Select Controller”, then under “Select Functions/Sequence” select Configuration.
Ensure “Normal” is selected under “Select Programming Type.” Click Next.

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.

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.
7.
8.

Record SPS Warranty Claim Code on job card for warranty transaction submission.
Repeat Steps 1 through 5 to confirm the correct tire size value was programmed.

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
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Customer Satisfaction Program
N232427140 Tire Size Reprogramming
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 program at no charge to customers, regardless of mileage, age of vehicle,
or ownership, through January 31, 2026. Customers who have recently purchased vehicles sold from your vehicle
inventory, and for which there is no customer information indicated on the involved vehicle listing, are to be contacted by
the dealer. Arrangements are to be made to make the required correction according to the instructions contained in this
bulletin. A copy of the customer letter is provided in this bulletin for your use in contacting customers. Program followup cards should not be used for this purpose, since the customer may not as yet have received the notification letter.
In summary, whenever a vehicle subject to this program enters your vehicle inventory or is in your facility for service
through January 31, 2026, you must take the steps necessary to be sure the program correction has been made before
selling or releasing the vehicle.
Dealer Reports – For USA & Export
For dealers with involved vehicles, a listing has been prepared and will be available through GM GlobalConnect Maxis
Field Action Reports or sent directly to export dealers. The Inventory tab of the dealer reports will contain 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 contain customer names and addresses from Motor Vehicle Registration
Records. The use of such motor vehicle registration data for any purpose other than follow-up necessary to complete
this field action may be a violation of law in several states.
Customer Notification
USA & Canada - General Motors will notify customers of this program on their vehicle (see copy of customer letter included
with this bulletin).

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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Customer Satisfaction Program
N232427140 Tire Size Reprogramming
December 2023
This notice applies to your vehicle, VIN: ________________________________
Dear General Motors Customer:
We have learned that your 2022 - 2023 model year Chevrolet 6500XD, equipped with tire size 255/70R22.5 may have a
calibration error where the vehicles were built with an incorrect tire size value. As a results, the speedometer will show
a vehicle speed higher than the actual vehicle speed while driving and the odometer will accumulate miles faster
(approximately 14% faster) than the “actual” or “True” vehicle miles. Additionally, mileage data collected and stored in
the Mimamori Unit (MMU), will be incorrect.
Your satisfaction with your Chevrolet 6500XD is very important to us, so we are announcing a program to prevent this
condition or, if it has occurred, to fix it.
What We Will Do: Your GM dealer will reprogram the engine control module and the mimamon unit. This service will
be performed for you at no charge until January 31, 2026. After that, any applicable warranty will apply.
What You Should Do: To limit any possible inconvenience, we recommend that you contact your dealer as soon as
possible to schedule an appointment for this repair. When scheduling your appointment, confirm with the dealer that
they service Medium Duty Trucks.
If you have any questions or concerns that your dealer is unable to resolve, please contact the appropriate Customer
Assistance Center at the number listed below.
For the hearing or speech impaired, please contact our Customer Assistance Center using the Telecommunication
Relay Service by dialing 711 then providing the appropriate Customer Assistance Center number for your vehicle.
Division
Chevrolet
Puerto Rico – English
Puerto Rico – Español
Virgin Islands

Number
1-800-222-1020
1-866-467-9700
1-866-467-9700
1-866-467-9700

Text Telephones (TTY)
711 / 1-800-833-2438

We truly appreciate you taking the time to update your vehicle as we know your time is valuable. We want you to know
that we will do our best, throughout your ownership experience, to ensure that your GM vehicle provides you many
miles of enjoyable driving.
Neelie O’Connor
Global Executive Director
Customer Experience Operations
N232427140

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