WenmarOpen by Wenmar Pro

Service bulletins for the 2021 Chevrolet Silverado

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.

1747 on file from NHTSA, as of 2026-10-19.

By type

By component

By trouble code

By topic

Only bulletins with component: Automatic transmission are shown. Show all

Bulletins, newest first
17-NA-0662023-07-25. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION; POWER TRAIN. This service bulletin provides information for automatic transmission Oil Cooler Flush and flow test.
PIP5926A2023-07-17. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT. This Preliminary information communicates that the t-case input seal, and/or the o-ring most likely is the source of the leak between the transmission and the t-case.
PIP5853C2023-05-15. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM). This PI communicates to dealers and technicians a possible diode issue in the TCCM, and how to properly diagnose for a diode issue.
16-NA-1302023-03-08. Service bulletin. POWER TRAIN; POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT:VALVES/VALVE BODY. This service bulletin provides information for after installation of a replacement upper valve body, the transmission may have no Reverse and no 2nd gear.
N2223808402022-11-17. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION. General Motors has decided to conduct a Voluntary Emissions Recall on certain vehicles with a 6.6L engine (RPO L8T). The Transmission Control Module (TCM) in these vehicles may have been service reprogrammed with incorrect calibrations. If this occurred, the transmission shift quality and timing could be degraded. Dealers are to reprogram the TCM.
PIP5621C2022-10-17. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); POWER TRAIN. This Preliminary information communicates to the dealer technician that TAC recommends the utilization of the GDS2 software to aid in diagnosing automatic transmission concerns. TAC is requesting the GDS2 session logs be sent in before the dealer contacts TAC.
22NA0222022-06-21. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT:SEALS/GASKETS. This Informational bulletin advises the technician of a possible oil leak at the front cover and how to diagnose it to verify if it is coming from the seal or not.
PIP58342022-03-14. Service bulletin. UNKNOWN OR OTHER; POWER TRAIN:AUTOMATIC TRANSMISSION. This Preliminary information communicates that the service 4wd message related to C119E is under investigation for a repair.
PIP57952022-03-14. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION. This Preliminary information communicates to technicians to replace the rear cover with seal in the event of a rear oil seal leak.
PIT5702C2022-02-14. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT:FILTER/SCREEN; EQUIPMENT. This Preliminary information communication provides information to the technician on installing Regular Production Option Code 9L7 Up-fitter Auxiliary Switches. Technician will need to reference the latest version of General Motors Up-fitter Integration Bulletin 153. The information can be found at http://www.gmupfitter.com/ under the "Technical Bulletin" Tab and then "Show all bulletins."
21NA1992022-02-14. Service bulletin. POWER TRAIN; POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT:VALVES/VALVE BODY. This informational bulletin advises the technician to replace the TBV if the transmission has any type of repair even if no problem was found, to replace the tbv.
990420002L2021-08-09. Service bulletin. POWER TRAIN:MANUAL TRANSMISSION; POWER TRAIN:AUTOMATIC TRANSMISSION; EQUIPMENT. This service bulletin provides information on Driveline Clunk Noise and what is acceptable and what is considered normal operation.
N2123280902021-04-26. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION. Customer Satisfaction Program. Certain 2021 model year Chevrolet Silverado 1500 and GMC Sierra 1500 vehicles, equipped with an 8 speed automatic transmission, (RPO MQE), may have a broken reaction carrier in the transmission. Dealers will replace the transmission.
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.
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.
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.

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