What causes a U0587 code?

U0587 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 U0587 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with U0587 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

U0587

Network/CAN bus communication code U0587

What it means

Invalid data received from the NOx Sensor 'B' (Outlet). The Engine Control Module (ECM) is receiving malformed data packets from the downstream sensor.