Service bulletins for the 2021 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.
1649 on file from NHTSA, as of 2026-10-19.
By type
By component
By trouble code
By topic
Only bulletins with component: Exhaust and emissions are shown. Show all
| 19-NA-044 | 2024-02-21. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL; FUEL SYSTEM, GASOLINE. This service bulletin provides information on the cold start control system in DI engines to reduce cold start emissions and improve fuel economy. |
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| 10-06-05-002M | 2023-08-28. Service bulletin. FUEL SYSTEM, DIESEL; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. This informational bulletin provides information on Clean Exhaust Filter See Owner Manual Now or Cleaning Exhaust Filter Keep Driving Until Message is Cleared messages Displayed on DIC, DTC P2463 May Be Set. |
| N232395310 | 2023-08-02. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL; FUEL SYSTEM, GASOLINE. Special Coverage - Certain vehicles may have a condition that could cause the evaporative emissions purge pump to fail. If this condition occurs, the Malfunction Indicator Light (Check Engine Light) will illuminate and a diagnostic trouble code will set. Dealers are to replace the evaporative emissions purge pump as necessary. The repairs will be made at no charge to the customer. The repairs will be made at no charge to the customer. |
| 22-NA-168 | 2023-04-14. Service bulletin. ENGINE AND ENGINE COOLING; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. This bulletin provides diagnostic information when checking the exhaust system for leaks. |
| 16-NA-380 | 2023-04-06. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM; ENGINE AND ENGINE COOLING. This service bulletin provides a diagnostic aid procedure on how to perform a quick test to check if the DPF is the cause of excessive soot from the tailpipe. |
| 16-NA-244 | 2023-04-06. Service bulletin. FUEL SYSTEM, DIESEL; ENGINE AND ENGINE COOLING; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. This informational bulletin provides information on Diesel Exhaust Fluid (DEF) and the proper use of the DEF system. |
| PIT5819A | 2023-02-13. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. This Preliminary information communicates in temperatures below freezing, it may be noticed that exhaust is only exiting from the right hand exhaust tailpipe. The cause of this condition is a low point in left side tailpipe which results in condensation building up at the low point in the tailpipe. In low temperatures the condensation can freeze and form ice limiting the flow of exhaust out of the left tailpipe. Dealers are to drill a small hole in the left tailpipe to allow condensation to drain. |
| 22-NA-168 | 2022-12-06. Service bulletin. ENGINE AND ENGINE COOLING; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. This bulletin provides diagnostic information when checking the exhaust system for leaks. |
| 22-NA-168 | 2022-10-12. Service bulletin. ENGINE AND ENGINE COOLING; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. This bulletin provides diagnostic information when checking the exhaust system for leaks. |
| 20-NA-082 | 2022-10-11. Service bulletin. FUEL SYSTEM, DIESEL; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL; ENGINE AND ENGINE COOLING. This informational bulletin explains why more DEF is being used in diesel engines due to new emission standards. |
| PIT5926A | 2022-08-15. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:MANIFOLD/HEADER/MUFFLER/TAIL PIPE. This Preliminary information communicates information on correcting a rattle noise from the underbody exhaust heat shield. |
| PIT5926 | 2022-07-25. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. This Preliminary information communicates information on correcting a rattle noise from the underbody exhaust heat shield |
| 21NA095 | 2022-06-21. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:MANIFOLD/HEADER/MUFFLER/TAIL PIPE. This technical bulletin provides a procedure to seal the exhaust at the UFSCR and Tailpipe flange. |
| PIE0665A | 2022-06-10. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM; ELECTRICAL SYSTEM; POWER TRAIN. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to Service Engine Soon (SES) Lamp illuminated and/or “Service Emissions System” message on the Driver Information Center (DIC). |
| 22-NA-110 | 2022-06-06. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM; ENGINE AND ENGINE COOLING. THis informational bulletin advises the tech not to replace the exhaust system if they smell plastic or rubber. |
| 19NA263 | 2022-05-31. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. This informational bulletin explains a normal condition for sludge to form in the oil cap when equipped with DEF system. |
| 19NA237 | 2022-05-31. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. This informational bulletin explains how to identify possible DEF contamination. |
| PIE0642A | 2021-08-09. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL; ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards the Service Engine Soon (SES) lamp illuminated and/or Service Emission System Message on the Driver Information Center (DIC). |
| 21NA095 | 2021-08-09. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. This technical bulletin provides a procedure to seal the exhaust at the UFSCR and Tailpipe flange. |
| PIT5819 | 2021-04-19. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:MANIFOLD/HEADER/MUFFLER/TAIL PIPE. This Preliminary information communicates in temperatures below freezing, it may be noticed that exhaust is only exiting from the right hand exhaust tailpipe. The cause of this condition is a low point in left side tailpipe which results in condensation building up at the low point in the tailpipe. In low temperatures the condensation can freeze and form ice limiting the flow of exhaust out of the left tailpipe. Dealers are to drill a small hole in the left tailpipe to allow condensation to drain. |
| 21NA007 | 2021-03-01. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL. This technical bulletin provides a procedure to program the reductant fluid module if found the cause of the customers concern. |
| 21NA006 | 2021-03-01. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL. This bulletin provides a possible location of a bad connection at the reductant fluid tanks electrical connector. |
| 20NA203 | 2021-03-01. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. This informational bulletin explains how the regen works for the DEF system and how it works at different levels. |
| PIE0601 | 2020-12-21. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to the Service Engine Soon Lamp being illuminated. |
| 100605002I | 2020-12-21. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM. This informational bulletin provides information on Clean Exhaust Filter See Owners Manual Now or Cleaning Exhaust Filter Keep Driving Until Message is Cleared messages Displayed on DIC, DTC P2463 May Be Set. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.