What causes a SPN 313 code?

SPN 313 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 313 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 313 active.

How do I fix SPN 313?

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 313

J1939 SPN 313 — Fuel/Air parameter

What it means

SPN 313 is a proprietary/generic fuel/air ratio or pressure parameter code indicating the ECM is receiving data that does not match expected operating conditions.