What causes a SPN 2043 code?

SPN 2043 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 2043 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 2043 active.

How do I fix SPN 2043?

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 2043

SPN 2043 - DEF Tank Temperature Fault

What it means

Indicates a diagnostic failure in the Diesel Exhaust Fluid (DEF) tank temperature sensor, showing an out-of-range signal or irrational reading to the Aftertreatment Control Module.