What causes a SPN 773 code?

SPN 773 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 773 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 773 active.

How do I fix SPN 773?

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 773

J1939 SPN 773 — Engine Management parameter

What it means

SPN 773 refers to the switch input used to increment engine speed, typically for Cruise Control or Power Take Off (PTO) operations.