Bulletin No.: 09-06-04-026Y

Service Bulletin

Date: August, 2024

INFORMATION
Subject:

Identifying Non-GM (Aftermarket) Engine Calibrations for Gasoline
Engines Using Tech 2® or GDS 2 (U.S. and Canada)

Models:

2007–2025 GM Passenger Cars and Light Duty Trucks – Equipped with
any V8 Gasoline Engine
2012–2025 GM Passenger Cars and Light Duty Trucks – Equipped with
any HFV6 Gasoline Engine
2019–2025 GM Passenger Cars and Light Duty Trucks – Equipped with
2.0L (RPO LSY) or 2.7L (RPO L3B) Gasoline Engines

Attention:

Refer to the GM Service Policy and Procedures Manual for the latest GM
Policy and Procedures Information.

This bulletin has been revised to add the 2025 Model Year. Please discard Corporate
Bulletin Number 09-06-04-026X.
Table of Contents
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.
• 1. Engine, Transmission, Transfer Case, Rear
Axle Components and Catalytic Converter
Failures Due to Non-GM ECM Calibrations
Being Installed
• 2. Calibration Retrieval and Calibration Verification Procedure for Service Agents NOT
REQUIRED to Call PQC for Powertrain/Drivetrain Assembly Replacement Authorization
• 3. Calibration Retrieval and Calibration Verification Procedure for Service Agents
REQUIRED to Call PQC for Powertrain/Drivetrain Assembly Replacement Authorization
• 4. Retrieving Engine Calibration ID and Verification No. (Number) Information Using the
Tech 2® - This Action is Required for ALL
Service Agents (Model Dependent)
• 5. Tech 2® Displaying All Zeroes for the Verification Numbers on the Vehicle Information -

Copyright 2024 General Motors. All Rights Reserved.

Calibration ID and Verification No. (Number/
CVN) Screen
• 6. Retrieving Calibration Information from
Global a Vehicles Using GDS 2 (Global A and
VIP Vehicles) - This Action is Required for ALL
Service Agents (Model Dependent)
• 7. Creating a .jpg or .jpeg File from a GDS 2
Calibration History Screen Shot Using
Microsoft Paint
• 8. Calibration Verification Procedure — For
Service Agents NOT REQUIRED to Call PQC for
Powertrain/Drivetrain Assembly Replacement
Authorization — Using the Tech 2® or GDS 2
8. A. Calibration Verification Procedure —
Using the Tech 2®
8. B. Calibration Verification Procedure —
Using GDS 2
• 9. Calibration Verification Procedure — For
Service Agents REQUIRED to Call PQC for
Powertrain/Drivetrain Assembly Replacement
Authorization — This Procedure MUST be
Performed by the Calibrations Group
• 10. Procedure for ALL Service Agents for Emailing .jpg or .jpeg Files to the Calibration
Group at — [email protected]
• 11. Calibrations Group - New E-mail Address [email protected]
• 12. Warranty Information

Page 2

August, 2024

1. Engine, Transmission, Transfer Case, Rear
Axle Components and Catalytic Converter
Failures Due to Non-GM ECM Calibrations
Being Installed
Notice:
• Be advised that GM REQUIRES retrieving the
Calibration Information and performing the
Calibration Verification Procedure as outlined in
this Bulletin, whenever diagnostics determine a
hard part failure may have occurred on internal
engine parts and BEFORE disassembly, repair
or replacement of an engine assembly under
warranty.
• Be advised that GM strongly recommends
retrieving the Calibration Information and
performing the Calibration Verification
Procedure as outlined in this Bulletin, whenever
diagnostics determine a hard part failure may
have occurred on transmission, transfer case or
rear axle components and before disassembly,
repair or replacement of a transmission, transfer
case or rear axle assembly under warranty. It is
also recommended that the ECM Calibration
Verification Procedure be performed whenever
diagnostics determine that catalytic converter
replacement is necessary.
• It is not a requirement to verify transmission
control module calibrations on gasoline engine
applications.
General Motors is identifying an increasing number of
engine, transmission and catalytic converter part
failures that are the result of non-GM ECM calibrations
being installed.
When alteration to the GM-released ECM calibration
occurs, it subjects powertrain and driveline components
such as engine, transmission, transfer case, driveshaft,
and the rear axle to stresses that were not tested by
General Motors. It is because of these unknown
stresses, and the potential to alter reliability, durability,
and emissions performance, that GM has adopted a
policy that prevents any UNAUTHORIZED Service
Agent Warranty Transaction submissions to any
remaining warranty coverage, to the powertrain and
driveline components whenever the presence of a nonGM calibration is confirmed, even if the non-GM ECM
calibration is subsequently removed.
Warranty coverage is based on the equipment and
ECM calibrations that were released on the vehicle at
time of sale, or subsequently updated by GM. That’s
because GM testing and validation matches the
calibration to a host of criteria that is essential to assure
reliability, durability and emissions performance over
the life of the warranty coverage and beyond. Stresses
resulting from calibrations that are different from those
tested and released by GM can damage and/or weaken
components, leading to poor performance and/or
shortened life.

Bulletin No.: 09-06-04-026Y

Additionally, non-GM issued ECM modifications often
do not meet the same emissions performance
standards as GM issued calibrations. Depending on
state statutes, individuals who install ECM calibrations
that put the vehicle outside the parameters of
emissions certification standards may be subject to
fines and/or penalties.
This bulletin outlines the Calibration Retrieval and
Calibration Verification Procedures for ALL Service
Agents including Service Agents NOT Required to Call
PQC for Powertrain/Drivetrain Assembly Replacement
Authorization and Service Agents Required to Call
PQC for Powertrain/Drivetrain Assembly Replacement
Authorization, using the Tech 2® or GDS 2 to identify
the presence of non-GM control module calibrations.
If a non-GM calibration is found and verification has
taken place through GM, the remaining powertrain and
driveline warranty may be blocked and notated in
Global Warranty Management (GWM) and the
dealership will be notified. This block prevents any
UNAUTHORIZED warranty claim submission.

2. Calibration Retrieval and Calibration
Verification Procedure for Service Agents NOT
REQUIRED to Call PQC for Powertrain/
Drivetrain Assembly Replacement
Authorization
Notice:
• The Service Agent Service Department
Personnel is NOT REQUIRED TO E-MAIL TAC
the digital Calibration Verification photos from
the Tech 2® screen or GDS 2 screen shot,
UNLESS non-GM calibrations are found.
• The Service Agent Service Department
Personnel is REQUIRED TO RETAIN ALL of the
related documentation showing the Calibration
Information was Retrieved and the Calibration
Verification Procedure was completed, in the
Service Agent Vehicle History Service File.
1. Depending on the vehicle being serviced, the
Service Department Personnel is required to
complete one of the following procedures, either
Step 1.1 or Step 1.2 in order to ensure that there
are not any non-GM ECM calibrations present:
1.1.

Section 4. Retrieving Engine Calibration
ID and Verification No. (Number) Information Using the Tech 2®
After retrieving the calibration information, Go to Step 2.
OR

1.2.

Section 6. Retrieving Calibration Information Using GDS 2 (Global A and VIP
Vehicles)
After retrieving the calibration information, Go to Step 2.

Bulletin No.: 09-06-04-026Y

August, 2024

2. After retrieving the Calibration Information and
performing Section: 8. Calibration Verification
Procedure — For Service Agents NOT
REQUIRED to Call PQC for Powertrain/Drivetrain Assembly Replacement Authorization —
Using the Tech 2® or GDS 2 the Service
Department Personnel is required to retain all of
the related documentation showing the procedures
were completed in the Service Agent Vehicle
History Service File.
⇒

If the Calibration Verification Procedure determines that THERE ARE non-GM ECM calibrations present, the Service Department
Personnel MUST follow the procedure as
instructed in: Section 10. Procedure for All
Service Agents for E-mailing .jpg or .jpeg
Files to the Calibration Group at —
[email protected]

3. When returning an engine assembly that is
requested through the WPC Parts Return Program,
a printed copy of the Tech 2® Vehicle Information
- Engine Calibration ID and Verification No.
(Number/CVN) screen or the GDS 2 Calibration
History (Events) screen shot must be attached to
the documentation being returned with the unit.
Notice: For additional information, refer to Service
Bulletins 20-NA-138 (U.S.) and 16-NA-338 (Canada
Only): Warranty Administration - Engine and Transmission Assembly Replacement and PQC Process.

3. Calibration Retrieval and Calibration
Verification Procedure for Service Agents
REQUIRED to Call PQC for Powertrain/
Drivetrain Assembly Replacement
Authorization
Notice:
• The Service Agent Service Department
Personnel is REQUIRED TO E-MAIL TAC the
digital Calibration Verification photos from the
Tech 2® screen or GDS 2 screen shot in .jpg
or .jpeg format only, to the following e-mail
address: [email protected]
• The Service Agent Service Department
Personnel is REQUIRED TO RETAIN ALL of the
related documentation showing the Calibration
Information was Retrieved and the Calibration
Verification Procedure was performed by the
Calibrations Group which is their e-mail
response, in the Service Agent Vehicle History
Service File.
1. Depending on the vehicle being serviced, the
Service Department Personnel is required to
complete one of the following procedures, either
Step 1.1 or Step 1.2 in order to ensure that there
are not any non-GM ECM calibrations present:
1.1.

Section 4. Retrieving Engine Calibration
ID and Verification No. (Number) Information Using the Tech 2®

Page 3
OR

1.2.

Section 6. Retrieving Calibration Information Using GDS 2 (Global A and VIP
Vehicles)
2. After retrieving the Calibration Information and
referring to Section: 9. Calibration Verification
Procedure — For Service Agents Required to
Call PQC for Powertrain/Drivetrain Assembly
Replacement Authorization — MUST be
Performed by the Calibrations Group, follow the
procedure in Section 10. Procedure for All
Service Agents for E-mailing .jpg or .jpeg Files
to the Calibration Group at —
[email protected]
3. The Service Department Personnel is required to
retain all of the related documentation showing the
procedures were completed in the Service Agent
Vehicle History Service File.
4. When returning an engine assembly that is
requested through the WPC Parts Return Program,
a printed copy of the Tech 2® Vehicle Information
- Engine Calibration ID and Verification No.
(Number/CVN) screen OR the GDS 2 Calibration
History (Events) screen shot must be attached to
the documentation being returned with the unit.

4. Retrieving Engine Calibration ID and
Verification No. (Number) Information Using
the Tech 2® - This Action is Required for ALL
Service Agents (Model Dependent)
Notice: This information applies to vehicles that are
Tech 2® compatible and is typical of the procedure
that will be used.
1. Connect the Tech 2® to the vehicle.
2. Go to: Diagnostics and build the vehicle.
3. Select: Powertrain.
4. Select: Engine.
5. Select: Engine Control Module or PCM.
6. Select: Module ID Information or I/M Information
System if the Module ID Information selection is
not available.
7. If: "I/M information System" was selected, it may
be necessary to select "Vehicle Information" in
order to display the calibration information.
⇒

If the CVN information is displayed as “N/A”, it
will be necessary to contact the TCSC at
1-800-828-6860 for English or 1-800-503-3222
for French to obtain the CVN information.

⇒

If the CVN Information is displayed as all
zeroes, refer to Section: 5. Tech 2®
Displaying All Zeroes for the Verification
Numbers on the Vehicle Information Calibration ID and Verification No. (Number/
CVN) Screen

Page 4

August, 2024

Bulletin No.: 09-06-04-026Y

5. Tech 2® Displaying All Zeroes for the
Verification Numbers on the Vehicle
Information - Calibration ID and Verification
No. (Number/CVN) Screen

2278650

2363198

If the Tech 2® that is being used displays all zeroes for
the Verification Numbers as shown, then perform the
following steps:
1. Update the Tech 2® with the latest software.
2. Turn OFF the ignition for 90 seconds.
3. Connect the Tech 2® to the vehicle.
4. Turn ON the ignition, and build the vehicle.
Observe the Tech 2® Vehicle Information Calibration ID and Verification No. (Number/CVN)
screen for proper operation.
⇒

2889412

If the Tech 2® screen still does not display
properly, then turn OFF the ignition for
90 seconds again. Turn ON the ignition and
observe the same screen for proper operation.

8. Take a CLEAR digital picture(s) of the Tech 2®
Vehicle Information screen showing the entire VIN,
(Engine) Calibration ID and Verification No.
(Number/CVN) and save it in .jpg format.

6. Retrieving Calibration Information Using
GDS 2 (Global A and VIP Vehicles) - This
Action is Required for ALL Service Agents
(Model Dependent)

9. Retain the printout information and the Tech 2®
screen photograph(s) with the repair order.

Notice: This information applies to Global A and
VIP - GDS 2 compatible vehicles and is typical of
the procedure that will be used.
1. Turn OFF the ignition.
2. Connect the MDI to the Data Link Connector (DLC)
of the vehicle.
3. Connect the MDI to a PC or laptop that has been
downloaded with the Techline Connect (TLC) and
the GDS 2 application.