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Cummins Engines · 1921
Aftertreatment Particulate Filter Differential Pressure High
What this code means
Aftertreatment Particulate Filter Differential Pressure - Data Valid But Above Normal Operating Range - Moderately Severe Level
Applies to: ISX CM871 (2007-2010).
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If diagnosis points to a failed sensor, solenoid, controller or harness part, send us the code (1921), machine model and serial number — we quote genuine and OEM replacement parts for export.
Ask for the replacement part on WhatsAppSource: Diesel Service Parts — Cummins ISX CM871 fault code list. Single published source — confirm against the manual for your exact model before ordering parts. Compiled 2026-10-30. No manufacturer affiliation.