WenmarOpen by Wenmar Pro

Service bulletins for the 2021 Chevrolet Trailblazer

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.

753 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

By topic

Only bulletins with component: Transmission and driveline are shown. Show all

Bulletins, newest first
20NA1382021-05-03. Service bulletin. ENGINE AND ENGINE COOLING; POWER TRAIN. This bulletin provides information on Policies Applicable to All U.S. Dealers for Engine and Transmission Assembly Replacement Under Warranty, Policy or Customer Enthusiasm and information on Submission of Warranty Transaction in Global Warranty Management.
N202321841 022021-04-26. Service bulletin. AIR BAGS; POWER TRAIN; EXTERIOR LIGHTING. Service Update. On certain vehicles equipped with automatic transmissions, the clutch spring retaining ring may not be fully seated. Vehicles with this condition may set DTC Code P0747 and the MIL light (malfunction indicator light) will illuminate. This typically occurs at low mileage. Dealers will inspect the transmission by following the procedure and if it fails, the transmission will be replaced.
N202321841 012021-04-26. Service bulletin. AIR BAGS; EXTERIOR LIGHTING; POWER TRAIN. Service Update. On certain vehicles equipped with automatic transmissions, the clutch spring retaining ring may not be fully seated. Vehicles with this condition may set DTC Code P0747 and the MIL light (malfunction indicator light) will illuminate. This typically occurs at low mileage. Dealers will inspect the transmission by following the procedure and if it fails, the transmission will be replaced.
PIP5712B2021-04-19. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:CRANK/CAMSHAFT POSITION SENSOR; POWER TRAIN. This Preliminary information communicates to the technician a service Diagnostic / Repair tip to avoid causing the crankshaft sprocket to disengage from the crankshaft during crankshaft balancer or cam drive system component related service procedures.
150089004C2021-03-08. Service bulletin. SUSPENSION:FRONT:MACPHERSON STRUT; SUSPENSION:FRONT:SHOCK ABSORBER; POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT. This service bulletin provides technicians with updated information to help identify the differences between what is considered a fluid leak, and what is considered fluid seepage.
21NA0042021-03-01. Service bulletin. POWER TRAIN; EQUIPMENT. This service bulletin provides information explaining possible normal CVT automatic transmission performance.
16NA0192021-02-22. Service bulletin. POWER TRAIN. This informational bulletin provides information on Transmission Adaptive Functions and Correcting Low Mileage Harsh Shifts, Slips, or Flares.
16NA0192021-02-01. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM:SOFTWARE. This informational bulletin provides information on Transmission Adaptive Functions and Correcting Low Mileage Harsh Shifts, Slips, or Flares.
PIE0587A2020-12-21. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION; ELECTRICAL SYSTEM:PROPULSION SYSTEM. This engineering information (EI) is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to loss of and/or reduced propulsion and multiple DTCs set.
060089031F2020-12-21. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION; ENGINE. This service bulletin provides information on OEM and Remanufactured Engine and Automatic Transmission/Transaxle Identification.
1308116001F2020-12-07. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM; POWER TRAIN:AUTOMATIC TRANSMISSION. The intent of this technical bulletin is to identify aftermarket ALDL or DLC interface devices as potential sources for causing multiple customer concerns that do not have other diagnostic methods to identify them.
20NA2102020-11-30. Service bulletin. ELECTRICAL SYSTEM:ADAS:HILL START ASSIST:SOFTWARE; POWER TRAIN:DRIVELINE:DIFFERENTIAL UNIT. This technical bulletin provides repair information to correct a customer concern of All-Wheel Drive Off and/or Service All-Wheel Drive System Messages Displayed in the DIC.
16NA0192020-10-26. Service bulletin. POWER TRAIN. This informational bulletin provides information on Transmission Adaptive Functions and Correcting Low Mileage Harsh Shifts, Slips, or Flares.
16NA3612020-09-28. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION. This informational bulletin explains possible normal condition of a flare from 1st to 2nd, even if the trans had been repaired for the flare and its still noticed.
20NA1202020-08-10. Service bulletin. POWER TRAIN. This informational bulletin explains how to check if the pulley and/or drive chain has any damage caused by low fluid or a code set that causes the transmission to default maxing out pressure.
A202299960 012020-07-20. Service bulletin. POWER TRAIN. Service Update - The gear shift lever may have a detent feel between Park and Reverse caused by the fastening bolt that is not fully seated and contacting the shifter housing. Dealers are to inspect the detent feel of the transmission range selector lever and replace the select cable if necessary.
A2023012302020-06-29. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM:SOFTWARE; ENGINE. 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.
19NA2002020-06-22. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); EQUIPMENT ADAPTIVE/MOBILITY. This technical bulletin provides a procedure to replace the transmission auxiliary pump to correct a condition of start/stop inoperative, MIL illuminated w/DTC P2797.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.