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Service bulletin 21NA257

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id10205577
Published by NHTSA2021-12-27
Manufacturer's number21NA257
Manufacturer's date2021-11-12
NHTSA componentENGINE AND ENGINE COOLING:COOLING SYSTEM; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT

NHTSA's summary

This service bulletin provides a service procedure to correct a customer concern of a Malfunction Indicator Lamp (MIL) Illuminated - DTC P3075 Set.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Engine, Equipment and accessories, Cooling system

Trouble codes named

P3075

Vehicles listed
BUICK ENCORE GX2020, 2021, 2022
CADILLAC CT42020, 2021, 2022
CADILLAC CT52020, 2021, 2022
CADILLAC XT42019, 2020, 2021, 2022
CADILLAC XT52020, 2021, 2022
CADILLAC XT62020, 2021, 2022
CHEVROLET BLAZER2019, 2020, 2021, 2022
CHEVROLET SILVERADO 15002019, 2020, 2021, 2022 (the catalog's model; the bulletin names a series or trim of it)
CHEVROLET TRAILBLAZER2021, 2022
GMC ACADIA2020, 2021, 2022
GMC SIERRA 15002019, 2020, 2021, 2022 (the catalog's model; the bulletin names a series or trim of it)

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Other bulletins for the same vehicles and component
22NA0132022-05-31. Service bulletin. This technical bulletin provides a procedure for the technician to check and tighten the CAC plumbing if found loose.
20NA1662022-05-31. Service bulletin. This informational bulletin advises the technician of possible coolant entering the areas of the engine, either through failed parts or defects in the castings, that may be the cause of the concerns related to the MIL or the engine running rough.
21NA2372022-02-14. Service bulletin. THis technical bulletin provides a procedure to perform a cooling system flush to remove possible debris from the cooling system pipes.
21NA2372021-12-27. Service bulletin. THis technical bulletin provides a procedure to perform a cooling system flush to remove possible debris from the cooling system pipes.
20NA0282021-12-20. Service bulletin. This service bulletin is to inform dealers that in extreme cold weather, a grille winter cover needs be added during PDI to avoid the customer returning with concerns related to charge air cooler icing.
18NA1032020-11-30. Service bulletin. This service bulletin provides information to correct a customer concern of an in-tank fuel pump whining noise, engine hard to start and/or stalls and Malfunction Indicator Lamp (MIL) is illuminated.
20NA1542020-09-28. Service bulletin. This Technical bulletin provides a procedure to correct a customer concern of a Flutter or Boom Noise around 1100 RPM.
20NA0282020-08-31. Service bulletin. This informational bulletin is to notify dealership personnel as well as providing the customer with the usage instructions from the owner manual, that in extreme cold weather (-18°C or less / 0°F or less), a grille winter cover needs be added during PDI to avoid the customer returning with concerns related to charge air cooler icing.
PIP5684B2020-08-10. Service bulletin. This Preliminary information communicates the use of air leak diagnostic test tool CH-52250 in addition to the information found in the service manual.
20NA0102020-06-22. Service bulletin. This technical bulletin provides a procedure to replace the cooling fan if found contacting the shroud causing the customers concern.