What causes a SPN 3003 code?

SPN 3003 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 3003 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3003 active.

How do I fix SPN 3003?

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 3003

J1939 SPN 3003 — Body/Chassis parameter

What it means

SPN 3003 refers to a status or data mismatch error originating from the Body or Chassis controller. In J1939 protocol, it often indicates a loss of communication or 'Data Erratic' from the Body/Chassis node.