Service bulletins for the 2018 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.
1345 on file from NHTSA, as of 2026-10-19.
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Only bulletins with component: Catalytic converter are shown. Show all
| 18209 | 2018-08-20. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:GASOLINE:TURBO/SUPERCHARGER; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:CATALYTIC CONVERTOR; ENGINE. 18209 - Service Update. Certain vehicles equipped with a 1.6L diesel engine (RPO LH7), may have been built with an improper alignment of the clamp/gasket assembly connecting the turbocharger to the catalytic converter. This condition may cause a diesel exhaust leak and/or smoke from the underhood area of the vehicle. In addition, a check engine indicator may set with diagnostic trouble code P0421. Dealers are to inspect and replace the turbocharger to catalytic converter clamp/gasket as necessary. |
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| 060601010D | 2018-06-04. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:CATALYTIC CONVERTOR. This informational bulletin explains how the catalytic converters may need an inspection, cleaning or replacement if debris have entered the exhaust system. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.