What causes a SPN 4813 code?

SPN 4813 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 4813 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 4813 active.

How do I fix SPN 4813?

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 4813

Engine Oil Thermostat Bypass Valve Opening

What it means

This code indicates that the engine oil thermostat bypass valve is stuck open or opening prematurely, preventing the engine oil from reaching its optimal operating temperature.