What causes a SPN 2003 code?

SPN 2003 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 2003 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 2003 active.

How do I fix SPN 2003?

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 2003

Transmission Controller Component Not Responding

What it means

The Engine Control Module (ECM) has lost communication with the Transmission Control Module (TCM) over the J1939 data link. This indicates a network timeout or a loss of power to the transmission controller.