What causes a SPN 355 code?

SPN 355 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 355 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 355 active.

How do I fix SPN 355?

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 355

J1939 SPN 355 — Fuel/Air parameter

What it means

SPN 355 is a generic parameter for 'Fuel/Air' ratio, typically indicating that the engine controller has detected an imbalance between the fuel supplied and the air intake, most commonly during the DPF regeneration process.