Service bulletins for the 2020 GMC Sierra
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.
1990 on file from NHTSA, as of 2026-10-19.
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Only bulletins with component: Automatic transmission are shown. Show all
| 19NA216 | 2019-10-28. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION. This technical bulletin provides the tech with a procedure to check the t-case for loose fasteners and to re-torque if the cause of the concern. |
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| 080730026F | 2019-09-23. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION. This informational bulletin provides information on Some vehicles may rock or move slightly forward or rearward while in Park at start up after cold soak. This condition may be accompanied by a clunk noise. This is a slight movement that is more often seen visually, rather than felt, when viewed from the outside and using the auto-start feature, if equipped. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.