What causes a SPN 1539 code?

SPN 1539 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 1539 code?

Drivability depends on the severity. Check the severity rating and verified driver reports on this page before continuing to drive with SPN 1539 active.

How do I fix SPN 1539?

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

Log in Sign up

J1939 SPN

SPN 1539

Engine Fan Speed High Side

What it means

Circuit fault on the high-voltage or power supply side of the fan control system.

Sign in to view symptoms, probable causes, diagnostic steps, severity, and related codes

Log in Sign up free