What causes a SPN 3739 code?

SPN 3739 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 3739 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3739 active.

How do I fix SPN 3739?

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 3739

J1939 SPN 3739 — Body/Chassis parameter

What it means

Body/Chassis Parameter Data - Abnormal Update Rate or Data Erratic. This is a generic J1939 fault indicating a communication or signal integrity issue between the engine/chassis controller and body equipment (e.g., crane, dump bed, lift gate).