What causes a SPN 855 code?

SPN 855 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 855 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 855 active.

How do I fix SPN 855?

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 855

J1939 SPN 855 — Engine Management parameter

What it means

Engine Management System parameter error. This code typically indicates a memory or checksum error within the ECM regarding powertrain management parameters.