P0400 on the 2016 Subaru Impreza
The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.
Nobody has written a description of this code yet.
| 11-197-20 | 2020-03-02. Service bulletin. This bulletin announces availability of reprogramming files to optimize the Engine Control Module (ECM). These new files address concerns of the check engine light coming on and setting a DTC P0400: EGR “A” FLOW. The DTC can set if the ECM tests the EGR system when ambient / intake air temperatures are below freezing. |
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1 on file from NHTSA, as of 2026-10-19. See them in the bulletin list. A bulletin lists model years: read the document for which vehicles it concerns.