What causes a SPN 3219 code?

SPN 3219 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 3219 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3219 active.

How do I fix SPN 3219?

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 3219

SPN 3219 Aftertreatment 1 Intake NOx Sensor Improper Connection

What it means

This fault indicates the Engine Control Module (ECM) has detected an irrational signal or communication failure with the inlet (pre-catalyst) NOx sensor.