GENERAL MOTORS
DCS7357
URGENT - DISTRIBUTE IMMEDIATELY
Date:

October 21, 2025

Subject: N252508350 - Special Coverage
Engine Coolant Thermostat
Models: 2021 Cadillac XT5
2021 Cadillac XT6
2021 Chevrolet Blazer
2021 GMC Acadia

General Motors is releasing Special Coverage N252508350 today.
What Should Dealers Do: Dealers can review the attached bulletin, and it will
also be displayed in Service Information tomorrow. This Special Coverage can
be seen in the Applicable Warranties section in Investigate Vehicle History (IVH).

END OF MESSAGE

Special Coverage
N252508350 Engine Coolant Thermostat
Release Date:
Attention:

October 2025

Revision:

00

This Special Coverage can be seen in the Applicable Warranties section in Investigate Vehicle History
(IVH).
Model Year

Make
Cadillac
Cadillac
Chevrolet
GMC

Model
XT5
XT6
Blazer
Acadia

From

To

2021

2021

Involved vehicles are identified on the Applicable Warranties section 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

Special
Coverage

Certain vehicles listed above, may have a condition that could cause the engine coolant thermostat to
open at a lower temperature than intended. If this condition were to occur, the Malfunction Indicator Lamp
(Check Engine Light) will illuminate and a diagnostic trouble code will set. Additionally in some cases,
the engine cooling fans may run after the engine is switched off.
This special coverage covers the condition described above for a period of 15 years or 150,000 miles
(240,000 km), whichever occurs first, from the date the vehicle was originally placed in service,
regardless of ownership.
For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or after
October 21, 2025, are covered by this special coverage and must be submitted using the labor operation
codes provided with this bulletin. Claims with repair orders prior to October 21, 2025, must be submitted
to the Service Contract provider.

Correction

Vehicle owners or lessees who paid for repairs referenced in this Special Coverage (“Customers”) are
eligible for reimbursement of their reasonable and customary expenses in accordance with the
procedures specified below. The conditional right to reimbursement is provided by GM solely in the
interest of customer satisfaction and is personal to Customers. Customers may not assign and GM
does not consent to any assignment of any Customer’s right to submit reimbursement claims, or to
receive reimbursement, or any other rights granted by this Special Coverage to any third party,
including but not limited to service contract providers, and this Special Coverage is not intended to and
does not confer any third party beneficiary, subrogation or contribution rights, or any other rights to
reimbursement, against GM, whether in law, equity or otherwise, on any third parties.
Dealers are to replace the engine coolant thermostat as necessary. The repairs will be made at no
charge to the customer.

Parts
Quantity
1
1
2
6
As Req’d

Part Name
HOUSING, ENG COOL THERM
SEAL, RAD OTLT PIPE (O RING)
SEAL, ENG COOL AIR BL PIPE (O RING)
SEAL, INT MANIFOLD
ENGINE COOLANT

Part No.
12741009
12623519
12648547
12648665
12346290 (US)
10953464 (CA)

Reminder: Parts may be removed from SPRINT and Retail Inventory Management (RIM) and be non-returnable.
Dealers should review the affected parts to confirm RIM managed status. Parts may have quantity limiters in effect.
Due to the limited initial parts availability, dealers are encouraged not to order these parts for use as shelf
stock.

Page 1 of 5

Special Coverage
N252508350 Engine Coolant Thermostat
Warranty Information
Labor
Operation
9900950
For vehicles
WITHIN the
Powertrain
Ltd
Warranty or
CPO
Powertrain
Ltd
Warranty,
utilize the
regular
warranty
labor op.
For vehicles
OUTSIDE
of the
Powertrain
Ltd
Warranty or
CPO
Powertrain
Ltd
Warranty,
utilize labor
op
9900951.
9900952

9900953

Description
Diagnostic Time Only – No Repair Required
Engine Coolant Thermostat Housing Replacement

Customer Reimbursement Approved
-For USA and Canada dealers only
-For Export dealers only
Customer Reimbursement Denied – For USA dealers Only

Labor
Time
0.1-.03
1.9

N/A
0.2
N/A

Trans.
Type
ZREG
ZREG

Net
Item
N/A
N/A

ZREG

*

ZREG

**

Note: The above labor time(s) are published direct from the Labor Time Guide.
Note: You may claim up to the allowable labor hours depending on actual time to perform electrical diagnosis.
*

For USA & Canada: Submit the dollar amount reimbursed to the Customer in Net/Reimbursement. Submit $20.00
USD ($25.00 CAD) administrative allowance in Net/Admin Allowance.
For Export: Submit the dollar amount reimbursed to the Customer in Net/Reimbursement.

** Submit $10.00 administrative allowance in Net/Admin Allowance.
Service Procedure
1.

2.

A vehicle may come in with DTC P0128 or other coolant thermostat related DTCs, coolant leaks from the thermostat
housing, or a complaint of engine cooling fans running after the vehicle has been shut off. Follow appropriate SI
diagnostics for these issues.
•

If the diagnostics lead to Engine Coolant Thermostat Housing Replacement, proceed to the next step.

•

If the diagnostics do NOT lead to Engine Coolant Thermostat Housing Replacement, the diagnostic time
needed to verify the thermostat housing may be covered under this field action, but further diagnosis or
repair will NOT.

Replace the Engine Coolant Thermostat Housing. Refer to Engine Coolant Thermostat Housing Replacement in SI.

Courtesy Transportation
USA - For repairs covered under this Field Action, Courtesy Transportation can be made available ONLY if the
customer/vehicle qualify for Courtesy Transportation per Bulletin 07-00-89-037.
Page 2 of 5

Special Coverage
N252508350 Engine Coolant Thermostat
Canada - Courtesy transportation is available for customers whose vehicles are involved in a product program and still
within the warranty coverage period. See General Motors Service Policies and Procedures Manual for courtesy
transportation program details. Refer to the most current Home Office Letter (YYYY-604) on the Courtesy
Transportation Program for details.
Customer Notification
General Motors will notify Customers of this special coverage on their vehicle (see copy of sample Customer letter
included with this bulletin).
Customer Reimbursement
Customer requests for reimbursement of previously paid repairs to correct the condition described in this bulletin are to
be submitted to the dealer prior to or by November 30, 2026. See General Motors Service Policies and Procedures
Manual (USA & Canada) or local Policies and Procedures, for details.

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

Page 3 of 5

Special Coverage
N252508350 Engine Coolant Thermostat

This notice applies to your vehicle, VIN: _____________________________________
Dear General Motors Customer:
As the owner of a GM vehicle, your satisfaction with our product is very important to us.
This letter is intended to make you aware that some vehicles may have a condition that could cause the engine coolant
thermostat to open at a lower temperature than intended. If this condition were to occur, the Malfunction Indicator Lamp
(Check Engine Light) will illuminate and a diagnostic trouble code will set. Additionally in some cases, the engine
cooling fans may run after the engine is switched off.
Do not take your vehicle to your GM dealer as a result of this letter unless you believe that your vehicle has the
condition as described above.
What We Have Done: General Motors is providing owners with additional protection for the condition described above.
If this condition occurs on your GM vehicle within 15 years of the date your vehicle was originally placed in service or
150,000 miles (240,000 km), whichever occurs first, the condition will be repaired for you at no charge. Diagnosis or
repair for conditions other than the condition described above is not covered under this special coverage program. For
customer’s vehicles already outside of the above years and/or miles, we are still offering reimbursement if the issue
occurred within the years and miles stated above. Please follow the reimbursement steps below.
What You Should Do: If you believe that your vehicle has the condition described above, repairs and adjustments
qualifying under this special coverage must be performed by a General Motors dealer. You may want to contact
your GM dealer to find out how long they will need to have your vehicle so that you may schedule the appointment at a
time that is convenient for you. This will also allow your dealer to order parts if they are not already in stock. Keep this
letter with your other important glove box literature for future reference.
Reimbursement: If you already paid for repairs for the condition described in this letter, and those repairs were
completed prior to this mailing, please complete the enclosed reimbursement form and present it to your dealer with
all required documents. Working with your dealer will expedite your request, however, if this is not convenient, you may
mail the completed reimbursement form and all required documents to Reimbursement Department, PO Box 33170,
Detroit, MI 48232-5170. The completed form and required documents must be presented to your dealer or received by
the Reimbursement Department by November 30,2026, unless state law specifies a longer reimbursement period.
The right to submit reimbursement claims is provided by GM solely in the interest of customer satisfaction and is
personal to vehicle owners and lessees who previously paid for repairs referenced in this Special Coverage
(“Customers”). Customers may not assign and GM does not consent to any assignment of any Customer’s right
to submit reimbursement claims, or to receive reimbursement, or any other rights granted by this Special
Coverage to any third party, including but not limited to service contract providers, and this Special Coverage
is not intended to and does not confer any third party beneficiary, subrogation or contribution rights, or any
other rights to reimbursement, against GM, whether in law, equity or otherwise, on any third parties.
You may schedule your vehicle for repair using the QR code below. For more information about your vehicle, or if you
have questions or concerns that your dealer is unable to resolve, please visit gm.com/service. You can also use your
preferred voice assistant (for example, “Alexa, go to gm/com/service”), or call the Buick, Chevrolet or GMC Customer
Assistance Center at 1-866-467-9700. For Cadillac, please call 1-800-333-4223.
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.
We are sorry for any inconvenience you may experience; however, we have taken this action in the interest of your
continued satisfaction with our products.
Neelie O’Connor
Global Executive Director
Customer Experience Operations
Scan here to
locate a dealer.

Page 4 of 5

Special Coverage
N252508350 Engine Coolant Thermostat

Enclosure
N252508350

Page 5 of 5