What causes a SPN 3066 code?

SPN 3066 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 3066 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3066 active.

How do I fix SPN 3066?

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 3066

Particulate Trap Outlet Pressure Data Out of Range

What it means

This fault indicates that the Diesel Particulate Filter (DPF) outlet pressure sensor is providing signals outside of the expected operating parameters or has failed altogether.