What causes a SPN 5985 code?

SPN 5985 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 5985 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 5985 active.

How do I fix SPN 5985?

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 5985

Cummins fault code 5985

What it means

Particulate Trap Differential Pressure - Data Valid but Above Normal Operating Range - Least Severe Level. This indicates high backpressure across the DPF.