What causes a SPN 3247 code?

SPN 3247 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 3247 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3247 active.

How do I fix SPN 3247?

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 3247

SPN 3247 FMI 3/4 Exhaust Gas Temperature 1 Out of Range

What it means

Indicates a voltage range fault in the Diesel Oxidation Catalyst (DOC) inlet temperature sensor circuit. This sensor monitors the heat entering the aftertreatment system to ensure proper regeneration.