Cummins fault code 3582 is logged by the electronic control module (ECM) on Cummins ISX11.9 and ISX15 CM2250 engines when it detects a SCR catalyst conversion efficiency problem recorded as Aftertreatment SCR Catalyst Conversion Efficiency – Data Valid But Below Normal Operating Range – Moderately Severe Level. This page in the DiagTechPro manuals library explains the SPN, FMI and lamp behaviour so a technician can plan the repair before the truck reaches the bay. Every entry in this library follows the same layout, so a workshop can move quickly from the dashboard warning to the correct wiring or component test.
What Cummins fault code 3582 means
Cummins identifies this event as SPN 4364, FMI 18, with an amber warning lamp. The ECM illuminates the amber CHECK ENGINE lamp when the diagnostic fails.
How the ECM sets this code
The ECM compares intake and outlet NOx readings to judge SCR catalyst conversion efficiency and sets this code when efficiency is below the normal range at a moderately severe level. Reading the exact SPN and FMI with a Cummins INSITE electronic service tool is the fastest way to confirm you are chasing the right circuit rather than a related aftertreatment code.
Possible causes and shop talk
The Cummins service information lists the following possible causes:
- Malfunctioning diesel exhaust fluid dosing system
- Exhaust system leaks
- Malfunctioning SCR catalyst
- Degraded, diluted or incorrect diesel exhaust fluid
- Diesel exhaust fluid deposits in the decomposition tube
This code can be set by several failure modes, so every step of the troubleshooting tree must be completed before condemning a part.
Clearing Cummins fault code 3582
Because fault code 3582 can share root causes with other SPN 4364 aftertreatment and engine codes, repair the confirmed fault, then restore the monitored conditions and check that the status changes to inactive in INSITE. This document was last revised in the ISX11.9 CM2250 fault code set by Cummins. Open the full step-by-step tree from the DiagTechPro manuals library, and confirm current bulletins through official Cummins engine support before finishing the job.
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