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P2421 on the 2021 Porsche Cayenne

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.

Bulletins for this model year that name P2421
No. 10-252026-02-06. Service bulletin. Technical information for Malfunction Indicator Light Active/Fault Memory Entry regarding Tank Shut-Off Valve Tank Ventilation System “P242100” or “P242200” in DME Control Unit
No. 10-252025-04-07. Service bulletin. Technical Information - Malfunction Indicator Light Active / Fault Memory Entry "P242100" or "P242200" in DME Control Unit: Observe Guided Troubleshooting (10 / 25)
No. 2412.22024-09-05. Service bulletin. Instructions on advanced technical information for the Cayenne DME - P242100 – Fuel Tank Isolation Valve for Tank Ventilation System
No. 2412.12024-08-06. Service bulletin. Instructions on advanced technical information for the Cayenne DME P242100 - fuel tank isolation valve for tank ventilation system - stuck open

4 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.