What causes a SPN 4270 code?

SPN 4270 can be triggered by several issues — see the verified probable causes and step-by-step diagnostics shared by mechanics and owners on OBDIY.

Can I drive with a SPN 4270 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 4270 active.

How do I fix SPN 4270?

Follow the step-by-step diagnostic on this page, then read the verified fixes contributed by other Heavy Truck owners — the answer marked "Verified Cause" worked for the original poster.

OBDIY

J1939 SPN

SPN 4270

Cummins fault code 4270

What it means

Aftertreatment 1 Intake NOx Sensor - Abnormal Update Rate. This means the Engine Control Module (ECM) has lost communication with the SCR inlet NOx sensor over the J1939 data link.