What causes a U0387 code?

U0387 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 U0387 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with U0387 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

U0387

Network/CAN bus communication code U0387

What it means

Software Incompatibility with Transfer Case Control Module. The software version in the TCCM does not align with the transmission or engine control requirements.