What causes a SPN 3204 code?

SPN 3204 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 3204 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3204 active.

How do I fix SPN 3204?

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 3204

J1939 SPN 3204 — Body/Chassis parameter

What it means

J1939 SPN 3204 refers to an Aftertreatment 1 Intake Dew Point issue or more commonly a general Body/Chassis Parameter Data error depending on the specific OEM implementation (often associated with software configuration or invalid data signals).