What causes a SPN 277 code?

SPN 277 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 277 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 277 active.

How do I fix SPN 277?

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 277

J1939 SPN 277 — Fuel/Air parameter

What it means

SPN 277 indicates an electrical or performance fault within the fuel injection timing control circuit. The ECM has detected that the timing actuator is not responding correctly to the commanded signal.