Service bulletins for the 2021 GMC Terrain
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.
696 on file from NHTSA, as of 2026-10-19.
By type
By component
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Only bulletins with component: Spark plugs are shown. Show all
| 21NA289 | 2022-02-14. Service bulletin. ELECTRICAL SYSTEM:IGNITION:COIL:SPARK PLUGS. This technical bulletin provides a procedure to inspect the ceramic portion of the sparkplug for cracking and to replace if found the cause of the customers concern. |
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| 21NA255 | 2021-12-27. Service bulletin. ELECTRICAL SYSTEM:IGNITION:COIL:SPARK PLUGS; ENGINE. This service bulletin provides repair information to correct a customer concern of an Engine Misfire, Malfunction Indicator Lamp (MIL) Illuminated - DTC P0300 Set. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.