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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: Engine are shown. Show all

Bulletins, newest first
010601011L2021-02-01. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. This informational bulletin provides guidelines and diagnostic/repair information to technicians regarding vehicle engine oil consumption.
20NA0842021-02-01. Service bulletin. ENGINE AND ENGINE COOLING. This service bulletin provides information on normal engine characteristics/noise produced by the LIH engine.
N2023219202021-02-01. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING. Service Update. A small number of vehicles may have a coolant inlet pipe that may present an obstructed threaded hole for the coolant temp sensor which could result in the check engine light coming on or a potential coolant leak. Dealers are to replace the coolant inlet pipe and temperature sensor.
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.
PIP57612020-12-14. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:CRANK/CAMSHAFT POSITION SENSOR. This Preliminary information communicates the possibility of a no start condition due crank sensor damage caused by increased crankcase pressure.
PIE05872020-12-07. Service bulletin. ENGINE AND ENGINE COOLING. 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.
A202317281 012020-11-30. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:CATALYTIC CONVERTOR. Emission Recall - General Motors has decided to conduct a voluntary emission recall on certain vehicles with a 1.2L engine (RPO LIH). These vehicles may have received incorrect catalytic converter parts that do not meet all emission system requirements. Dealers are to inspect the catalytic converter and replace if the correct part was not installed.
A2023172812020-11-30. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:CATALYTIC CONVERTOR. Emission Recall - General Motors has decided to conduct a voluntary emission recall on certain vehicles with a 1.2L engine (RPO LIH). These vehicles may have received incorrect catalytic converter parts that do not meet all emission system requirements. Dealers are to inspect the catalytic converter.
16NA2222020-11-30. Service bulletin. ENGINE. This bulletin provides information on Engine Concerns that could result from lack of scheduled maintenance, improper service or aftermarket calibrations.
PIP57582020-11-16. Service bulletin. ENGINE AND ENGINE COOLING. This Preliminary information communicates to the dealer technician a diagnostic tip related to a tapping noise from the engine.
20NA1652020-10-26. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; STRUCTURE:BODY; ENGINE. This technical bulletin provides repair information to correct a customer concern of Flutter or Boom Noise at 1200 RPM- Service Calibration.
20NA0282020-10-26. Service bulletin. ENGINE AND ENGINE COOLING. This 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.
A2023172802020-10-26. Service bulletin. ENGINE AND ENGINE COOLING. Stop Delivery. Incorrect emission parts may have been installed on these vehicles.
PIP5692B2020-10-19. Service bulletin. ENGINE. This Preliminary Information communication advises the technician that the engine exchange program on vehicles equipped with engine Regular Production Option Code LIH has ended. This engine can now be ordered through the regular General Motors Customer Care and Aftersales parts process or Product Quality Center process for required dealers.
PIP5691B2020-10-19. Service bulletin. ENGINE AND ENGINE COOLING. This Preliminary Information communication advises the technician that the engine exchange program on vehicles equipped with engine Regular Production Option Code L3T has ended. This engine can now be ordered through the regular General Motors Customer Care and Aftersales parts process or Product Quality Center process for required dealers.
20NA0282020-08-31. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; ENGINE AND ENGINE COOLING:COOLING SYSTEM; EQUIPMENT ADAPTIVE/MOBILITY. 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.
PIP57392020-08-10. Service bulletin. ENGINE AND ENGINE COOLING. This Preliminary information communicates specific directions for the application of room temperature vulcanizing (RTV) sealant to the engine Lower Crankcase Extension during engine oil pan installation.
PIP57342020-08-10. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING:ENGINE:OIL/LUBRICATION:PUMP; FUEL SYSTEM, GASOLINE. This Preliminary information communicates to the dealer a testing procedure to isolate a potential Engine Oil Pump Switching issue.
A2023048402020-07-20. Service bulletin. ENGINE; EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY. SUB - Certain 2020-2021 Buick Encore GX and 2021 Chevrolet Trailblazer vehicles may have a condition where the camshaft actuator oil control valve (OCV) center bolt could stick or bind. If this were to happen, it could cause a MIL light to illuminate on the dash (Service Engine Soon), setting diagnostic trouble codes (DTC?s) P0011 or P0014, the engine could run rough and have reduced power. Dealers will inspect for these DTC?s that could have been set by this condition, and pass or fail based on results.
A202302140 012020-07-20. Service bulletin. FUEL SYSTEM, GASOLINE; ENGINE. Service Update - On certain vehicles, the engine oil pump may be stuck due to foreign material, and diagnostic trouble codes (DTC) P0521, P06DE, P06DD could be set. Dealers are to perform the engine oil pump screening test and if necessary, replace the oil pump.
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.
16NA3832020-06-22. Service bulletin. ENGINE; FUEL SYSTEM, GASOLINE:FUEL INJECTION SYSTEM; EQUIPMENT ADAPTIVE/MOBILITY. This technical bulletin advises of a new fuel injection cleaner kit used for decarbonizing the intake valves to correct conditions of rough idle, Crank no start, extended crank or misfire, MIL with DTCs, and explains how Top Tier fuels should be used to reduce carbon build-up.
20NA0842020-05-26. Service bulletin. ENGINE. This informational bulletin advises of normal engine noise produced by the engine.
PIP5692A2020-05-11. Service bulletin. ENGINE AND ENGINE COOLING. The Preliminary Information communication advises the technician that there is a part restriction for the 1.2L LIH engine. The dealer technician is advised to call the GM Product Quality Center for further assistance.
PIP5691A2020-05-11. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. The Preliminary Information communication advises the technician that there is a part restriction for the 1.3L L3T engine. The dealer technician is advised to call the GM Product Quality Center for further assistance.

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