Service bulletins for the 2021 Subaru Ascent
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.
384 on file from NHTSA, as of 2026-10-19.
By type
By component
By trouble code
Only bulletins with component: Exhaust and emissions are shown. Show all
| 09-110-23 | 2023-11-06. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:CATALYTIC CONVERTOR. This Service Information Bulletin announces diagnostic service procedures to be followed when DTC P0420 (Catalyst System Efficiency Below Threshold Bank 1) is detected by the Engine Control Module (ECM). If DTC P0420 is found to be stored in the ECM, follow the diagnostic procedures outlined below. |
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| 09-106-23 | 2023-08-02. Service bulletin. ENGINE AND ENGINE COOLING; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:MANIFOLD/HEADER/MUFFLER/TAIL PIPE; EQUIPMENT. This bulletin announces design changes made to the Exhaust Pipe Front (EPF) to address concerns of rattle-type or fluttering sounds coming from the undercarriage during acceleration caused by cracking in the EPF. |
| 11-204-23 | 2023-05-02. Service bulletin. ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL:CRANKCASE (PCV); ENGINE AND ENGINE COOLING. This Service Information Bulletin announces a design change made to the Positive Crankcase Ventilation (PCV) hose assembly. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.