What causes a SPN 2034 code?

SPN 2034 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 2034 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 2034 active.

How do I fix SPN 2034?

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 2034

SPN 2034 FMI 5 Diesel Exhaust Fluid Controller Current

What it means

Indicates an electrical fault where the Aftertreatment Diesel Exhaust Fluid (DEF) controller or dosing valve circuit is detecting an open circuit or low current condition.