What causes a SPN 1869 code?

SPN 1869 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 1869 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 1869 active.

How do I fix SPN 1869?

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 1869

SPN 1869: SCR Catalyst Differential Pressure Data Erratic

What it means

This fault indicates that the Selective Catalytic Reduction (SCR) differential pressure sensor is reporting values that are inconsistent, erratic, or outside of the expected physiological range.