What causes a SPN 335 code?

SPN 335 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 335 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 335 active.

How do I fix SPN 335?

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 335

J1939 SPN 335 — Fuel/Air parameter

What it means

J1939 SPN 335 indicates an out-of-range or implausible reading between the fuel delivery system and the air intake system, signaling a combustion imbalance.