What causes a U3430 code?

U3430 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 U3430 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with U3430 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

U3430

Manufacturer-specific network code U3430

What it means

Lost communication with the Telematics Control Unit (TCU). The truck can no longer send remote diagnostics or location data back to the fleet manager.