What causes a SPN 307 code?

SPN 307 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 307 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 307 active.

How do I fix SPN 307?

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 307

J1939 SPN 307 — Fuel/Air parameter

What it means

Generic J1939 fault related to the Fuel/Air ratio or air induction parameters. It signifies that the ECM has detected data that does not match expected volumetric efficiency tables.