What causes a SPN 395 code?

SPN 395 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 395 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 395 active.

How do I fix SPN 395?

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 395

J1939 SPN 395 — Fuel/Air parameter

What it means

SPN 395 is a general J1939 parameter for Air/Fuel Control, often indicating a specific failure in the lift pump circuit or a critical deviation in fuel pressure relative to air intake.