What causes a SPN 3586 code?

SPN 3586 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 SPN 3586 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 3586 active.

How do I fix SPN 3586?

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

J1939 SPN

SPN 3586

J1939 SPN 3586 — Body/Chassis parameter

What it means

Brake Switch 2 / Secondary Brake Input - Abnormal frequency, pulse width, or period. This code typically monitors the redundancy between the primary and secondary brake signal inputs for cruise control and PTO safety.