What causes a SPN 3392 code?

SPN 3392 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 3392 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3392 active.

How do I fix SPN 3392?

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 3392

J1939 SPN 3392 — Body/Chassis parameter

What it means

DEF Level Sensor Signal implausible or out of range. Indicates the ECM is receiving data regarding the DEF tank level that is inconsistent with expected values or other sensor inputs.