What causes a P0590 code?

P0590 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 P0590 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with P0590 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

P0590

Cruise Control Multi-Function Input B Circuit High

What it means

The engine control module (ECM) has detected a voltage signal on the cruise control input 'B' circuit that is higher than the calibrated limit, often indicating a short to power or a stuck switch.