What causes a U0349 code?

U0349 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 U0349 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with U0349 active.

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

OBD-II

U0349

Software Incompatibility with Trailer Brake Control Module

What it means

Communication software conflict for trailers with electronic brakes. This is critical for heavy-duty towing safety.