WenmarOpen by Wenmar Pro

Service bulletin 20NA028

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 id10178966
Published by NHTSA2020-08-31
Manufacturer's number20NA028
Manufacturer's date2020-07-09
NHTSA componentEQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; ENGINE AND ENGINE COOLING:COOLING SYSTEM; EQUIPMENT ADAPTIVE/MOBILITY

NHTSA's summary

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.

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, Labels and manuals, Cooling system

Vehicles listed
BUICK ENCORE2020
CHEVROLET TRAILBLAZER2021

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
21NA2572021-12-27. Service bulletin. This service bulletin provides a service procedure to correct a customer concern of a Malfunction Indicator Lamp (MIL) Illuminated - DTC P3075 Set.
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.
20NA0242020-04-06. Service bulletin. This informational bulletin provides a information and diagnostic steps/tips for vehicles that are slow to heat up in cold temperatures.