What causes a P1408 code?

P1408 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 P1408 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P1408 active.

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

OBD-II

P1408

CCVCD pressure too high fault

What it means

Crankcase ventilation centrifugal separator speed too high or pressure deviation. The engine's crankcase pressure is not being properly regulated by the spinning separator.