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Service bulletin 20NA165

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 id10181697
Published by NHTSA2020-10-26
Manufacturer's number20NA165
Manufacturer's date2020-09-08
NHTSA componentELECTRICAL SYSTEM:SOFTWARE; STRUCTURE:BODY; ENGINE

NHTSA's summary

This technical bulletin provides repair information to correct a customer concern of Flutter or Boom Noise at 1200 RPM- Service Calibration.

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

Body and frame, Electrical system, Engine, Software

Vehicles listed
BUICK ENCORE GX2021
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
20-NA-1322024-04-05. Service bulletin. This warranty administration bulletin provides policy information on the requirements for 12V battery testing and warranty replacements.
PIP5632G2023-01-30. Service bulletin. This Preliminary Information communication provides information to the technician that General Motors Technical Assistance Center may ask for Global Diagnostic System 2 Session Log. Technician will need use Global Diagnostic System 2 to send the session logs to General Motors Technical Assistance Center for further assistance on the vehicle in question.
PIP4902Q2023-01-30. Service bulletin. This Preliminary Information communication provides information to the technician that General Motors Technical Assistance Center may ask for Global Diagnostic System 2 Session Log. Technician will need use Global Diagnostic System 2 to send the session logs to General Motors Technical Assistance Center for further assistance on the vehicle in question.
21NA2562022-02-14. Service bulletin. This service bulletin provides repair information for dealers/technicians to correct a customer concern of a Malfunction Indicator Lamp Illuminated with DTC P26BB Set.
21NA1452021-08-09. Service bulletin. This service bulletin provides U157 software update information to correct customer concerns of radio Software related issues.
20NA2372021-02-22. Service bulletin. This service bulletin provides V152 radio software update information to correct customer concerns of various software issues.
20NA2372021-02-01. Service bulletin. This service bulletin provides V152 radio software update information to correct customer concerns of various software issues.
16NA0192021-02-01. Service bulletin. This informational bulletin provides information on Transmission Adaptive Functions and Correcting Low Mileage Harsh Shifts, Slips, or Flares.
PIP57462020-09-14. Service bulletin. This Preliminary information communicates the possibility of the vehicle having dtc P2B95 in history and possibly P2B96 P2B0A, P2B08, or P2B09 due to a software anomally.
A2023012302020-06-29. Service bulletin. SUB - Certain 2021 model year Chevrolet Trailblazer, and 2020-2021 model year Buick Encore GX vehicles, equipped with a continuously variable ratio (CVT) transmission, may experience reduced launch performance during a quick exit from a stop/start event. DTC?s P0746 and P0776 may also set illuminating a Check Engine Light. The main pump in the CVT has a priming delay under certain conditions. Dealers will reprogram the transmission control module (TCM) with updated software.