What causes a SPN 3220 code?

SPN 3220 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 3220 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3220 active.

How do I fix SPN 3220?

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 3220

SPN 3220 FMI 2 / 12 Aftertreatment 1 Intake NOx Sensor

What it means

The Engine Control Module (ECM) has detected an irrational or failed signal from the Intake NOx Sensor located at the turbocharger outlet/SCR inlet.