What causes a SPN 445 code?

SPN 445 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 445 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 445 active.

How do I fix SPN 445?

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 445

J1939 SPN 445 — Fuel/Air parameter

What it means

SPN 445 is a general parameter group for Fuel/Air management. It indicates that the Engine Control Module (ECM) has detected an imbalance or out-of-range value regarding the stoichiometry or fueling ratios required for current load conditions.